Bump Microsoft.AspNetCore.Mvc.Testing from 5.0.3 to 5.0.4

Bumps [Microsoft.AspNetCore.Mvc.Testing](https://github.com/dotnet/aspnetcore) from 5.0.3 to 5.0.4.
- [Release notes](https://github.com/dotnet/aspnetcore/releases)
- [Commits](dotnet/aspnetcore@v5.0.3...v5.0.4)

Signed-off-by: dependabot[bot] <support@github.com>

Directory.Packages.props

@@ -1,7 +1,7 @@
 <Project>
   <ItemGroup>
     <PackageVersion Include="coverlet.msbuild" Version="3.0.3" />
-    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="5.0.3" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="5.0.4" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="1.0.0" />
     <PackageVersion Include="Moq" Version="4.16.1" />