Runs gettext by default

What does this MR do and why?

Runs gettext by default on pre-push

The performance of generating translations was greatly increased (9d3f4829), which means we can run it before pushing. This should save some unnecessary broken pipelines.

How to set up and validate locally

1. Add or change a translation to a file (eg https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/ml/experiment_tracking/routes/experiments/index/translations.js#L14)

2. run lefthook run pre-push. Task gettext should fail and show that some lines are changed

3. run lefthook run auto-fix. This should update locale/gitlab.pot

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.