fix(ci): install git in builder and pass token for private dependency

The builder image needs git to clone the schwab-scraper SSH dependency.
Uses git insteadOf to redirect SSH URLs to HTTPS with CR_PAT in CI.

.gitea/workflows/build.yaml

@@ -28,3 +28,5 @@ jobs:
           context: .
           push: true
           tags: gitea.ext.ben.io/${{ gitea.repository }}:latest
+          build-args: |
+            GIT_TOKEN=${{ secrets.CR_PAT }}