ci: retry apt-get install up to 3 times on network failure

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -28,7 +28,12 @@ jobs:
           node -e "const fs=require('fs'),p=JSON.parse(fs.readFileSync('package.json')); p.version='$VERSION'; fs.writeFileSync('package.json', JSON.stringify(p, null, 2)+'\n')"
 
       - name: Install Linux build deps
-        run: apt-get update && apt-get install -y --fix-missing python3 make g++ libgtk-3-dev libnss3-dev libxss1 libasound2-dev libgbm-dev dpkg fakeroot zip
+        run: |
+          for i in 1 2 3; do
+            apt-get update && apt-get install -y --fix-missing python3 make g++ libgtk-3-dev libnss3-dev libxss1 libasound2-dev libgbm-dev dpkg fakeroot zip && break
+            echo "apt attempt $i failed, retrying in 10s..."
+            sleep 10
+          done
 
       - name: Build Linux (deb + zip)
         run: pnpm make