Apply suggestions from code review

Co-authored-by: Ivan Maximov <[email protected]>

Author: mburumaxwell

test/Serilog.Extensions.Hosting.Tests/SerilogServiceCollectionExtensionsTests.cs

@@ -17,7 +17,7 @@ public void ServicesAreRegisteredWhenCallingAddSerilog()
             collection.AddSerilog();
 
             // Assert
-            IServiceProvider provider = collection.BuildServiceProvider();
+            using var provider = collection.BuildServiceProvider();
             provider.GetRequiredService<ILoggerFactory>();
             provider.GetRequiredService<IDiagnosticContext>();
         }
@@ -49,7 +49,7 @@ public void ServicesAreRegisteredWhenCallingAddSerilogWithConfigureDelegate()
             collection.AddSerilog(_ => { });
 
             // Assert
-            IServiceProvider provider = collection.BuildServiceProvider();
+            using var provider = collection.BuildServiceProvider();
             provider.GetRequiredService<ILogger>();
             provider.GetRequiredService<ILoggerFactory>();
             provider.GetRequiredService<IDiagnosticContext>();