Disable the checks for PO files

You can revert this commit once the CI environment has a recent enough
gettext version.
6 jobs for 178-purge-the-useless-code in 70 minutes and 5 seconds (queued for 1 second)
Status Job ID Name Coverage
  Dist
passed dist #649124

00:40:41

 
  Check
passed check #649125

00:04:20

passed deb #649127

00:09:40

passed mingw #649126

00:24:05

 
  Manual
passed pages #649128

00:05:18

 
  Deploy
passed pages:deploy

00:00:02