Bump MSTest.TestAdapter

Bumps [MSTest.TestAdapter](https://github.com/microsoft/testfx) from 3.0.2 to 3.0.3.
- [Release notes](https://github.com/microsoft/testfx/releases)
- [Changelog](https://github.com/microsoft/testfx/blob/main/docs/Changelog.md)
- [Commits](microsoft/testfx@v3.0.2...v3.0.3)

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

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

Author: dependabot[bot]

docs/core/tutorials/snippets/library-with-visual-studio-6-0/csharp/StringLibraryTest/StringLibraryTest.csproj

@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="3.0.2" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.0.3" />
     <PackageReference Include="MSTest.TestFramework" Version="3.0.3" />
     <PackageReference Include="coverlet.collector" Version="6.0.0" />
   </ItemGroup>