ci: 修复preview-cleanup checkout不兼容Gitea Actions问题 (#545)

Co-authored-by: xiaoxia <dev@xiaoxiajianji.com>
Co-committed-by: xiaoxia <dev@xiaoxiajianji.com>

.gitea/workflows/preview-cleanup.yml

@@ -16,7 +16,50 @@ jobs:
     timeout-minutes: 10
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      shell: sh
+      env:
+        GITHUB_TOKEN: ${{ github.token }}
+      run: |
+        set -eu
+        python3 - <<'PY'
+        import io, os, tarfile, time, urllib.request, urllib.error
+        url = f"{os.environ['GITHUB_API_URL']}/repos/{os.environ['GITHUB_REPOSITORY']}/archive/{os.environ['GITHUB_SHA']}.tar.gz"
+        request = urllib.request.Request(url, headers={"Authorization": f"token {os.environ['GITHUB_TOKEN']}"})
+        last_err = None
+        for attempt in range(5):
+            try:
+                with urllib.request.urlopen(request, timeout=120) as response:
+                    archive = response.read()
+                break
+            except urllib.error.HTTPError as e:
+                last_err = e
+                if e.code >= 500 and attempt < 4:
+                    wait = 2 ** attempt
+                    print(f"Checkout HTTP {e.code}, retrying in {wait}s (attempt {attempt+1}/5)...")
+                    time.sleep(wait)
+                    continue
+                raise
+            except Exception as e:
+                last_err = e
+                if attempt < 4:
+                    wait = 2 ** attempt
+                    print(f"Checkout error: {e}, retrying in {wait}s (attempt {attempt+1}/5)...")
+                    time.sleep(wait)
+                    continue
+                raise
+        else:
+            raise last_err
+        with tarfile.open(fileobj=io.BytesIO(archive), mode='r:gz') as tar:
+            root_prefix = tar.getmembers()[0].name.split('/', 1)[0] + '/'
+            for member in tar.getmembers():
+                name = member.name
+                if name == root_prefix[:-1]:
+                    continue
+                if name.startswith(root_prefix):
+                    member.name = name[len(root_prefix):]
+                if member.name:
+                    tar.extract(member, '.')
+        PY
 
     - name: Extract PR number
       shell: sh