fix(ci): install git in Alpine container before checkout

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: andinux

.github/workflows/main.yml

@@ -83,6 +83,10 @@ jobs:
 
     steps:
 
+      - name: install git for alpine container
+        if: matrix.container
+        run: apk add --no-cache git
+
       - uses: actions/checkout@v4.2.2
         with:
           submodules: true