Remove the guards around M.D.SqlClient V4 in tests (#7541)

## Summary of changes

there was a piece of code skipping some tests in v4 and above of the
library. Those were added in #2077 referencing
dotnet/SqlClient#1390
However, this check has stayed in place ever since, stopping tests from
being run on newer versions, even though the issue says that the issue
was fixed in 4.0.1 if I read correctly. Since we don't run tests on
v4.0.0 (the lowest 4 we run on is 4.0.6), we shouldn't need to check for
this anymore.
This might have been kept around because of an other issue where the
sample app encountered an authentication issue trying to connect to the
server in docker because the security certificate was not proper. Adding
`TrustServerCertificate` on the connection string fixes this, and should
allow us to run all tests always.

## Reason for change

better test coverage for SqlClient

## Implementation details

## Test coverage

ran a pipeline testing all package versions for this test here:
https://dev.azure.com/datadoghq/dd-trace-dotnet/_build/results?buildId=187543

## Other details
<!-- Fixes #{issue} -->


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Author: vandonr

docker-compose.yml

@@ -432,7 +432,7 @@ services:
       - ELASTICSEARCH7_HOST=elasticsearch7:9200
       - ELASTICSEARCH6_HOST=elasticsearch6:9200
       - ELASTICSEARCH5_HOST=elasticsearch5:9200
-      - SQLSERVER_CONNECTION_STRING=Server=sqlserver;User=sa;Password=Strong!Passw0rd
+      - SQLSERVER_CONNECTION_STRING=Server=sqlserver;User=sa;Password=Strong!Passw0rd;TrustServerCertificate=true
       - POSTGRES_HOST=postgres
       - MYSQL_HOST=mysql
       - MYSQL_PORT=3306
@@ -713,7 +713,7 @@ services:
       - ELASTICSEARCH7_HOST=elasticsearch7_arm64:9200
       - ELASTICSEARCH6_HOST=elasticsearch7_arm64:9200
       - ELASTICSEARCH5_HOST=elasticsearch7_arm64:9200
-      - SQLSERVER_CONNECTION_STRING=Server=sqledge_arm64;User=sa;Password=Strong!Passw0rd
+      - SQLSERVER_CONNECTION_STRING=Server=sqledge_arm64;User=sa;Password=Strong!Passw0rd;TrustServerCertificate=true
       - POSTGRES_HOST=postgres_arm64
       - MYSQL_HOST=mysql_arm64
       - MYSQL_PORT=3306

tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/AdoNet/MicrosoftDataSqlClientTests.cs

@@ -47,24 +47,7 @@ public async Task SubmitsTraces(
             // - IDbCommandGenericConstraint<SqlCommand>: 7 spans (1 group * 7 spans)
             // - IDbCommandGenericConstraint<SqlCommand>-netstandard: 7 spans (1 group * 7 spans)
 
-            // version 4.0 : 91 spans
-            // - SqlCommand: 21 spans (3 groups * 7 spans)
-            // - DbCommand:  21 spans (3 groups * 7 spans)
-            // - IDbCommand: 7 spans (1 groups * 7 spans)
-            // - DbCommand-netstandard:  21 spans (3 groups * 7 spans)
-            // - IDbCommand-netstandard: 7 spans (1 groups * 7 spans)
-            // - IDbCommandGenericConstraint<SqlCommand>: 7 spans (1 group * 7 spans)
-            // - IDbCommandGenericConstraint<SqlCommand>-netstandard: 7 spans (1 group * 7 spans)
-            var isVersion4 = !string.IsNullOrWhiteSpace(packageVersion)
-                          && new Version(packageVersion) >= new Version("4.0.0");
-
-            if (isVersion4 && FrameworkDescription.Instance.OSPlatform != OSPlatformName.Windows)
-            {
-                // Version 4.0.0 has an issue on Linux https://github.com/dotnet/SqlClient/issues/1390
-                return;
-            }
-
-            var expectedSpanCount = isVersion4 ? 91 : 147;
+            var expectedSpanCount = 147;
             const string dbType = "sql-server";
             const string expectedOperationName = dbType + ".query";
 

tracer/test/test-applications/integrations/Samples.Microsoft.Data.SqlClient/Program.cs

@@ -17,17 +17,9 @@ private static async Task<int> Main()
 
             using (var connection = OpenConnection(typeof(SqlConnection)))
             {
-                if (connection is null)
-                {
-                    Console.WriteLine("No connection could be established. Exiting with skip code (13)");
-                    return 13;
-                }
-                
                 await RelationalDatabaseTestHarness.RunAllAsync<SqlCommand>(connection, commandFactory, commandExecutor, cts.Token);
             }
 
-            // Version 4.0.0 causes a hard crash
-#if !SQLCLIENT_4
             // Test the result when the ADO.NET provider assembly is loaded through Assembly.LoadFile
             // On .NET Core this results in a new assembly being loaded whose types are not considered the same
             // as the types loaded through the default loading mechanism, potentially causing type casting issues in CallSite instrumentation
@@ -37,36 +29,39 @@ private static async Task<int> Main()
                 // Do not use the strongly typed SqlCommandExecutor because the type casts will fail
                 await RelationalDatabaseTestHarness.RunBaseClassesAsync(connection, commandFactory, cts.Token);
             }
-#endif
+
             // allow time to flush
             await Task.Delay(2000, cts.Token);
             return 0;
         }
 
         private static DbConnection OpenConnection(Type connectionType)
         {
-            int numAttempts = 3;
+            var remainingAttempts = 3;
             var connectionString = Environment.GetEnvironmentVariable("SQLSERVER_CONNECTION_STRING") ??
 @"Server=(localdb)\MSSQLLocalDB;Integrated Security=true;Connection Timeout=60";
 
-            for (int i = 0; i < numAttempts; i++)
+            DbConnection connection = null;
+            retry:
+            try
             {
-                DbConnection connection = null;
-
-                try
-                {
-                    connection = Activator.CreateInstance(connectionType, connectionString) as DbConnection;
-                    connection.Open();
-                    return connection;
-                }
-                catch (Exception ex)
+                connection = Activator.CreateInstance(connectionType, connectionString) as DbConnection;
+                connection.Open();
+                return connection;
+            }
+            catch (Exception ex)
+            {
+                if (remainingAttempts > 0)
                 {
                     Console.WriteLine(ex);
                     connection?.Dispose();
+                    remainingAttempts--;
+                    goto retry;
                 }
-            }
 
-            return null;
+                // else
+                throw;
+            }
         }
     }
 }

tracer/test/test-applications/integrations/Samples.Microsoft.Data.SqlClient/Samples.Microsoft.Data.SqlClient.csproj

@@ -2,7 +2,6 @@
 
   <PropertyGroup>
     <ApiVersion Condition="'$(ApiVersion)' == ''">2.0.1</ApiVersion>
-    <DefineConstants Condition="'$(ApiVersion)'&gt;='4.0.0'">$(DefineConstants);SQLCLIENT_4</DefineConstants>
 
     <!-- Required to build multiple projects with the same Configuration|Platform -->
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>