fix: allow merge non-translations pull requests

The `validate-translation-files.yml` workflow is now required, but it runs only on
PRs in which `translations/**` have been edited.

This causes the non-translation pull requests to be blocked from
merging because the `validate-translation-files.yml` won't run depite
being required.

.github/workflows/validate-translation-files.yml

@@ -4,8 +4,6 @@ name: Validate translation PO files
 
 on:
   pull_request:
-    paths:
-      - 'translations/**'
 
 jobs:
   validate-po-files: