ci: 使用 registry 缓存替代 gha 缓存

Docker 构建缓存改为存储在镜像仓库中，兼容 Gitea Actions

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/deploy.yaml

@@ -45,8 +45,8 @@ jobs:
           tags: |
             ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-web:${{ steps.meta.outputs.tag }}
             ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-web:latest
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-web:buildcache
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-web:buildcache,mode=max
 
       - name: Build and push API image
         uses: docker/build-push-action@v6
@@ -57,8 +57,8 @@ jobs:
           tags: |
             ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-api:${{ steps.meta.outputs.tag }}
             ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-api:latest
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-api:buildcache
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-api:buildcache,mode=max
 
   deploy:
     name: Deploy to Knative