Fix handling of submodule paths

[sanmai-NL]

If the workspace directory was a submodule, MegaLinter would consider this a valid Git working copy to detect changed files in. However, the .git directory may not be accessible from within the submodule, e.g., when the submodule was mounted inside a container as subpath, without ../.git.

Proposed Changes

1. Skip listing updated files when the .git directory is not a descendant of the workspace directory.

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]

@sanmai-NL fix the flake8 issue (line too long) and i'll validate :)

[sanmai-NL]

@nvuillam Should be done. Can be tested by starting a container with the submodule directory bind-mounted to /tmp/lint.

[nvuillam]

@sanmai-NL I don't have expertise in git submodules, but it looks clean so I merged ;)

Please can you confirm it works well with beta version ?