move container image into job

.gitea/workflows/release_preparation.yaml

@@ -8,11 +8,12 @@ on:
 
 jobs:
     update-deps:
+        container:
+            image: gitea.champs-libres.be/chill-project/chill-skeleton-basic/base-image:latest
         steps:
             - name: check out repository
               uses: https://github.com/actions/checkout@v4
             - name: run composer update to update composer.lock
-              uses: docker://gitea.champs-libres.be/chill-project/chill-skeleton-basic/base-image:latest
               run: composer update
             - name: commit changed files
               uses: stefanzweifel/git-auto-commit-action@v5