Bump MSTestVersion from 3.2.2 to 3.3.1

Bumps `MSTestVersion` from 3.2.2 to 3.3.1.

Updates `MSTest.TestAdapter` 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](microsoft/testfx@v3.2.2...v3.3.1)

Updates `MSTest.TestFramework` 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](microsoft/testfx@v3.2.2...v3.3.1)

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

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

test/Directory.Build.props

@@ -12,7 +12,7 @@
   </ItemGroup>
 
   <PropertyGroup>
-    <MSTestVersion>3.2.2</MSTestVersion>
+    <MSTestVersion>3.3.1</MSTestVersion>
   </PropertyGroup>
 
   <ItemGroup>