ci: replace actions/checkout with native git clone

.gitea/workflows/ci.yml

@@ -7,11 +7,11 @@ on:
 jobs:
   build-and-deploy:
     runs-on: docker
-    container:
-      image: docker:cli
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
+      - name: Clone code
+        run: |
+          git clone https://git.plfai.cn/test/fastapi-demo.git .
+          git checkout ${GITHUB_SHA}
 
       - name: Docker Build
         run: |
@@ -26,7 +26,7 @@ jobs:
           docker push registry.plfai.cn/fastapi-demo:${GITHUB_SHA:0:7}
           docker push registry.plfai.cn/fastapi-demo:latest
 
-      - name: Deploy
+      - name: ArgoCD Sync
         run: |
           curl -sk -o /dev/null -X POST \
             -H "Authorization: Bearer ${{ secrets.ARGOCD_TOKEN }}" \