Bump actions/upload-artifact from 6 to 7 (UniversalRobots#449)

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -112,15 +112,15 @@ jobs:
           mkdir -p ursim_logs/flightreports
           docker cp ursim:/ursim/flightreports/. ursim_logs/flightreports/
       - name: Upload logfiles
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         if: ${{ always() &&  steps.check_polyscopex.outputs.is_polyscopex  == 'false' }}
         with:
           name: ${{matrix.env.ROBOT_MODEL}}_${{matrix.env.URSIM_VERSION}}_URSim_Logs
           path: ursim_logs
           if-no-files-found: error
           retention-days: 10
       - name: Upload test artifacts
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         if: ${{ always() &&  steps.check_polyscopex.outputs.is_polyscopex  == 'false' }}
         with:
           name: ${{matrix.env.ROBOT_MODEL}}_${{matrix.env.URSIM_VERSION}}_test_artifacts