Bump actions/upload-artifact from 5 to 6 (#2860)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/dotnet-build-and-test.yml

@@ -225,7 +225,7 @@ jobs:
 
       - name: Upload coverage report artifact
         if: matrix.targetFramework == env.COVERAGE_FRAMEWORK
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: CoverageReport-${{ matrix.os }}-${{ matrix.targetFramework }}-${{ matrix.configuration }} # Artifact name
           path: ./TestResults/Reports # Directory containing files to upload

.github/workflows/python-test-coverage.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Run all tests with coverage report
         run: uv run poe all-tests-cov --cov-report=xml:python-coverage.xml -q --junitxml=pytest.xml
       - name: Upload coverage report
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           path: |
             python/python-coverage.xml