Bump the dotnet group with 1 update (#46873)

Bumps MSTest from 3.9.2 to 3.9.3

---
updated-dependencies:
- dependency-name: MSTest
  dependency-version: 3.9.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dotnet
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]