chore(deps): update actions/upload-artifact action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Run tests - ${{ matrix.name }}
         run: xcodebuild test -scheme "flex-ui" -destination "${{ matrix.destination }}" -enableCodeCoverage YES -resultBundlePath "test_output/${{ matrix.name }}.xcresult" clean || exit 1
       - name: Upload test results
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: ${{ matrix.name }}
           path: test_output