fix(ci): checkout for image refs step

.forgejo/workflows/functions.yml

@@ -13,11 +13,6 @@ jobs:
           - blob-proxy
     runs-on: ubuntu-latest
     steps:
-      - name: Setup Git config
-        run: |
-          git config --global user.email "ci@icb4dc0.de"
-          git config --global user.name "Forgejo Actions"
-
       - name: Setup `spin`
         uses: fermyon/actions/spin/setup@v1
 
@@ -52,6 +47,14 @@ jobs:
     needs:
       - build
     steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Git config
+        run: |
+          git config --global user.email "ci@icb4dc0.de"
+          git config --global user.name "Forgejo Actions"
+
       - name: Update image reference
         run: |
           for func in "comics", "blob-proxy":