chore: move checkov output to REPORT_FOLDER

[gmeligio]

Proposed Changes

1. Write checkov SARIF report in REPORT_FOLDER instead of DEFAULT_WORKSPACE, removing the need of adding the generated results.sarif to .gitignore when running megalinter locally.
2. When passing --output-file-path, checkov automatically changes the report file name from results.sarif to results_sarif.sarif.

Readiness Checklist

Author/Contributor

• Add entry to the CHANGELOG listing the change and linking to the corresponding issue (if appropriate)
• If documentation is needed for this change, has that been included in this pull request

Reviewing Maintainer

• Label as breaking if this is a large fundamental change
• Label as either automation, bug, documentation, enhancement, infrastructure, or performance

[nvuillam]

Good catch, thanks a lot for your contribution @gmeligio :)

[gmeligio]

Thank you for the review @nvuillam !