build(deps): Bump MSTest.TestAdapter from 3.2.2 to 3.3.1

Bumps [MSTest.TestAdapter](https://github.com/microsoft/testfx) from 3.2.2 to 3.3.1.
- [Release notes](https://github.com/microsoft/testfx/releases)
- [Changelog](https://github.com/microsoft/testfx/blob/main/docs/Changelog.md)
- [Commits](https://github.com/microsoft/testfx/compare/v3.2.2...v3.3.1)

---
updated-dependencies:
- dependency-name: MSTest.TestAdapter
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Xdg.Testing/Xdg.Testing.csproj

@@ -13,7 +13,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
-		<PackageReference Include="MSTest.TestAdapter" Version="3.2.2" />
+		<PackageReference Include="MSTest.TestAdapter" Version="3.3.1" />
 		<PackageReference Include="MSTest.TestFramework" Version="3.3.1" />
 		<PackageReference Include="coverlet.collector" Version="6.0.2" />
 	</ItemGroup>