ESLint needs to ignore /vendor folder

In run-local-checks.sh we have catered for this by adding --ignore-pattern=vendor --ignore-pattern=node_modules so could do the same in the gitlab job. But I think it may be tidier to use a .eslintignore file, which can be active for both local and the pipeline job.

Looks good.

Merged. Thanks!

The command line in run-local-scripts.sh now matches the command in our .gitlab-ci.yml which is a "good thing"

But I noticed that the 'check code' job is already green, so those prettier failures must have been fixed upstream or something.
https://git.drupalcode.org/project/gitlab_templates/-/merge_requests/377...
Still it is good that we have this .eslintignore file anyway.