fix(ci): remove redundant DEV_IMAGE variable and use REGISTRY directly for image tags

.gitea/workflows/test.yml

@@ -8,7 +8,6 @@ on:
 
 env:
   REGISTRY: git.arthurerlich.de
-  DEV_IMAGE: git.arthurerlich.de/${{ gitea.repository }}:ci-${{ gitea.sha }}
 
 jobs:
   build-dev:
@@ -34,7 +33,7 @@ jobs:
           file: Dockerfile.dev
           target: dev
           push: true
-          tags: ${{ env.DEV_IMAGE }}
+          tags: ${{ env.REGISTRY }}/${{ gitea.repository }}:ci-${{ gitea.sha }}
           cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository }}:buildcache-dev
           cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository }}:buildcache-dev,mode=max
 
@@ -60,7 +59,7 @@ jobs:
     needs: build-dev
     runs-on: ubuntu-latest
     container:
-      image: ${{ env.DEV_IMAGE }}
+      image: ${{ env.REGISTRY }}/${{ gitea.repository }}:ci-${{ gitea.sha }}
       credentials:
         username: ${{ gitea.actor }}
         password: ${{ secrets.REGISTRY_TOKEN }}