Revert "Bump codecov/codecov-action from 3 to 4 (open-telemetry#2314)" (open-telemetry#2315)

Author: marcalff

.github/workflows/ci.yml

@@ -810,7 +810,7 @@ jobs:
         CXX: /usr/bin/g++-10
       run: ./ci/do_ci.sh code.coverage
     - name: upload report
-      uses: codecov/codecov-action@v4
+      uses: codecov/codecov-action@v3
       with:
         file: /home/runner/build/coverage.info