Fixed failure to run .NET 6 tests

Error:
Testhost process exited with error: Error:
  An assembly specified in the application dependencies manifest (Serilog.Sinks.MSSqlServer.Tests.deps.json) was not found:
    package: 'Azure.Core', version: '1.6.0'
    path: 'lib/netstandard2.0/Azure.Core.dll'
. Please check the diagnostic logs for more information.

Solution found here: https://stackoverflow.com/a/73548949/2586938

Author: ckadluba

test/Serilog.Sinks.MSSqlServer.Tests/Serilog.Sinks.MSSqlServer.Tests.csproj

@@ -2,7 +2,6 @@
 
   <PropertyGroup>
     <TargetFrameworks>net462;net472;net6.0</TargetFrameworks>
-    <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netstandard2.0</TargetFrameworks>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <AssemblyName>Serilog.Sinks.MSSqlServer.Tests</AssemblyName>
     <AssemblyOriginatorKeyFile>../../assets/Serilog.snk</AssemblyOriginatorKeyFile>
@@ -11,6 +10,7 @@
     <PackageId>Serilog.Sinks.MSSqlServer.Tests</PackageId>
     <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
     <RuntimeIdentifiers>win</RuntimeIdentifiers>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
     <PlatformTarget>AnyCPU</PlatformTarget>
   </PropertyGroup>