Bump Microsoft.AspNetCore.Mvc.Testing and System.Text.Json in /src (#778)

Bumps [Microsoft.AspNetCore.Mvc.Testing](https://github.com/dotnet/aspnetcore) and [System.Text.Json](https://github.com/dotnet/runtime). These dependencies needed to be updated together.

Updates `Microsoft.AspNetCore.Mvc.Testing` from 8.0.8 to 8.0.10
- [Release notes](https://github.com/dotnet/aspnetcore/releases)
- [Changelog](https://github.com/dotnet/aspnetcore/blob/main/docs/ReleasePlanning.md)
- [Commits](dotnet/aspnetcore@v8.0.8...v8.0.10)

Updates `System.Text.Json` from 8.0.4 to 8.0.5
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v8.0.4...v8.0.5)

---
updated-dependencies:
- dependency-name: Microsoft.AspNetCore.Mvc.Testing
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: System.Text.Json
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -8,7 +8,7 @@
     <PackageVersion Include="EfLocalDb" Version="19.1.1" />
     <PackageVersion Include="EntityFramework" Version="6.5.1" />
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="27.0.2" />
-    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.10" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore" Version="8.0.10" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.8" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Relational" Version="8.0.10" />