Bump Microsoft.NET.Test.Sdk from 17.8.0 to 17.9.0

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 17.8.0 to 17.9.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](microsoft/vstest@v17.8.0...v17.9.0)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Directory.Build.props

@@ -18,7 +18,7 @@ Upgraded to Phobos 2.0.6</PackageReleaseNotes>
     <LibraryFramework>netstandard2.0</LibraryFramework>
     <XunitVersion>2.6.6</XunitVersion>
     <XunitRunnerVersion>2.5.3</XunitRunnerVersion>
-    <TestSdkVersion>17.8.0</TestSdkVersion>
+    <TestSdkVersion>17.9.0</TestSdkVersion>
     <PbmVersion>1.3.2</PbmVersion>
     <OTelVersion>1.6.0</OTelVersion>
     <OTelInstrumentationVersion>1.5.1-beta.1</OTelInstrumentationVersion>