Bump MSTest.TestAdapter from 3.0.4 to 3.1.1

Bumps [MSTest.TestAdapter](https://github.com/microsoft/testfx) from 3.0.4 to 3.1.1.
- [Release notes](https://github.com/microsoft/testfx/releases)
- [Changelog](https://github.com/microsoft/testfx/blob/main/docs/Changelog.md)
- [Commits](microsoft/testfx@v3.0.4...v3.1.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tests/TurnerSoftware.SitemapTools.Tests/TurnerSoftware.SitemapTools.Tests.csproj

@@ -20,7 +20,7 @@
 		<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />
 		<PackageReference Include="Microsoft.AspNetCore.TestHost" Version="2.2.0" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.3" />
-		<PackageReference Include="MSTest.TestAdapter" Version="3.0.4" />
+		<PackageReference Include="MSTest.TestAdapter" Version="3.1.1" />
 		<PackageReference Include="MSTest.TestFramework" Version="3.1.1" />
 		<PackageReference Include="coverlet.collector" Version="6.0.0">
 			<PrivateAssets>all</PrivateAssets>