Currently Crowdin is syncing the Kabyle language with the language code
kab_KAB. This locale code cannot be detected by gettext, as this tool
detects locale codes that only have 2 characters after the underscore.

This is causing the `gettext:regenerate` command to delete the
`locale/kab_KAB/gitlab.po` file every time it is run.

This change:

1. Update the Crowdin config to map `kab_KAB` to just `kab`
1. Deletes `kab_KAB` locale file (which currently has 0% translation
   anyway).

Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/235511

- https://gitlab.com/gitlab-org/gitlab/-/issues/227184

As recommended by the folks at Crowdin

This is an undocumented feature of the Crowdin configuration.

This will append `[skip ci]` to all commit messages from Crowdin,
avoiding 100s of pipelines to be created.

The pipeline will need to be run manually for these merge requests
instead.

And add the project_identifier & api key to be able to work with Crowdin-CLI