super-linter: Don't require full Git environment validation when users enable IGNORE_GITIGNORED_FILES

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Upgrading from v5 to v6 is resulting in .git /action/lib/functions/validation.sh: line 202: GITHUB_SHA: unbound variable error.

Expected Behavior

For super-linter container to run correctly.

Super-Linter version

v6 & slim-v6

Relevant log output

/action/lib/functions/validation.sh: line 202: GITHUB_SHA: unbound variable.

Steps To Reproduce

Running the following command

docker run --rm \
    -v "$(git rev-parse --show-toplevel):/tmp/lint" \
    -e DEFAULT_WORKSPACE=/tmp/lint \
    -e SUPPRESS_POSSUM=true \
    -e RUN_LOCAL=true \
    -e USE_FIND_ALGORITHM=true \
    -e LINTER_RULES_PATH=".dsop/linters" \
    ghcr.io/super-linter/super-linter:slim-v6

Error shows up locally and on Gitlab pipeline. Downgrading to v5 fixes this issue.

Anything else?

No response