[gimp-help/wip/wormnest/validate] ci: add pip install polib needed by validate_po.py

[Jacob Boerema <jboerema src gnome org>]

commit c4545649d1817574767049fe95940c7507cc438d
Author: Jacob Boerema <jgboerema gmail com>
Date:   Sat Jul 23 13:34:22 2022 -0400

    ci: add pip install polib needed by validate_po.py

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f7cf7b378..1bb86e83d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -33,6 +33,7 @@ po-validate:
   stage: validatepo
   image: $CI_REGISTRY_IMAGE:build-debian-latest
   script:
+    - pip install polib
     - cd po
     - find . -type f -print0 | xargs -0 ../tools/validate_po.py $1 $2
   needs: ["build-image"]