The workflow is not valid. .github/workflows/cicd.yaml (Line: 28, Col: 19): Unexpected symbol: '$DOCKER_HUB_USR'. Located at position 9 within expression: secrets.$DOCKER_HUB_USR .github/workflows/cicd.yaml (Line: 29, Col: 19): Unexpected symbol: '$DOCKER_HUB_PASS'. Located at position 9 within expression: secrets.$DOCKER_HUB_PASS