Update codecov/codecov-action action to v6

Signed-off-by: Mend Renovate <bot@renovateapp.com>

Author: renovate-bot

.github/workflows/operator.yml

@@ -175,7 +175,7 @@ jobs:
         run: make test
 
       - name: Upload test coverage
-        uses: codecov/codecov-action@671740ac38dd9b0130fbe1cec585b89eea48d3de # v5.5.2
+        uses: codecov/codecov-action@57e3a136b779b570ffcdbf80b3bdc90e7fab3de2 # v6.0.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./cover.out