chore(deps): bump the github-actions group with 2 updates

Bumps the github-actions group with 2 updates: [actions/download-artifact](https://github.com/actions/download-artifact) and [actions/upload-artifact](https://github.com/actions/upload-artifact).


Updates `actions/download-artifact` from 5 to 6
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

Updates `actions/upload-artifact` from 4 to 5
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

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

Author: dependabot[bot]

.github/workflows/flaky.yaml

@@ -59,7 +59,7 @@ jobs:
           echo TESTS_RESULT=$result
           echo "TESTS_RESULT=$result" >>"$GITHUB_ENV"
       - name: download nextest reports
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           pattern: libtest_run_${{ github.run_number }}-${{ github.run_attempt }}-*
           merge-multiple: true

.github/workflows/tests.yaml

@@ -125,7 +125,7 @@ jobs:
 
     - name: upload results
       if: ${{ failure() && inputs.flaky }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v5
       with:
         name: libtest_run_${{ github.run_number }}-${{ github.run_attempt }}-${{ matrix.name }}_${{ matrix.features }}_${{ matrix.rust }}.json
         path: output
@@ -227,7 +227,7 @@ jobs:
 
     - name: upload results
       if: ${{ failure() && inputs.flaky }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v5
       with:
         name: libtest_run_${{ github.run_number }}-${{ github.run_attempt }}-${{ matrix.name }}_${{ matrix.features }}_${{ matrix.rust }}.json
         path: output