ci: fix build cache path

.gitea/workflows/gentoo-utils.yml

@@ -15,17 +15,17 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:
-      - name: Checkout repo
-        uses: actions/checkout@v5
-        with:
-          fetch-depth: 0
-
       - name: Restore git cache
         uses: actions/cache@v4
         with:
           path: .git
           key: gitea-repo-${{ gitea.repository }}-${{ gitea.ref }}
 
+      - name: Checkout repo
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
       - name: Detect Changes
         uses: dorny/paths-filter@v3
         id: image-changes