ci: 依赖 GitHub 托管环境的任务在镜像站上跳过

macOS 构建、systemd 安装测试、Docker 镜像与发布只在 github.com 上运行，
Gitea 等镜像站的 runner 只跑 Go 测试。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -13,6 +13,7 @@ permissions:
 jobs:
   binaries:
     name: Server & agent binaries
+    if: github.server_url == 'https://github.com'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -32,6 +33,7 @@ jobs:
 
   macos-app:
     name: macOS app
+    if: github.server_url == 'https://github.com'
     runs-on: macos-15
     steps:
       - uses: actions/checkout@v4
@@ -53,7 +55,7 @@ jobs:
   docker:
     name: Docker image
     runs-on: ubuntu-latest
-    if: startsWith(github.ref, 'refs/tags/v')
+    if: github.server_url == 'https://github.com' && startsWith(github.ref, 'refs/tags/v')
     steps:
       - uses: actions/checkout@v4
       - uses: docker/setup-qemu-action@v3
@@ -86,7 +88,7 @@ jobs:
     name: GitHub release
     needs: [binaries, macos-app]
     runs-on: ubuntu-latest
-    if: startsWith(github.ref, 'refs/tags/v')
+    if: github.server_url == 'https://github.com' && startsWith(github.ref, 'refs/tags/v')
     steps:
       - uses: actions/download-artifact@v4
         with: