chore: add hadolint_flags for JSON output in CI workflow

- Introduce hadolint_flags with '--format json' to enhance output formatting
- Improve integration and readability of Hadolint results in CI process

Author: kzndotsh

.github/workflows/ci.yml

@@ -144,6 +144,7 @@ jobs:
           filter_mode: ${{ env.REVIEWDOG_FILTER_MODE }}
           fail_level: ${{ env.REVIEWDOG_FAIL_LEVEL }}
           hadolint_ignore: DL3008 DL3009 DL3007
+          hadolint_flags: '--format json'
   yaml:
     name: YAML
     runs-on: ubuntu-latest