switch to use Actions from drone for cron (#24314)

Move drone cron pipelines to (GitHub) Actions. As these are mostly
compatible with Gitea Actions, when we start to dogfood, these will
already be migrated.

.github/workflows/cron-licenses.yml

@@ -0,0 +1,28 @@
+on:
+  cron:
+    # weekly on Monday at 0:07 UTC
+    - cron: "7 0 * * 1"
+
+name: Update licenses and gitignores
+
+jobs:
+  cron:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - uses: actions/setup-go@v3
+        with:
+          go-version: '>=1.20.1'
+      - name: update licenses and gitignores
+        run: timeout -s ABRT 40m make generate-license generate-gitignore
+      - name: push translations to repo
+        uses: appleboy/git-push-action@v0.0.2
+        with:
+          author_email: "teabot@gitea.io"
+          author_name: GiteaBot
+          branch: main
+          commit: true
+          commit_message: "[skip ci] Updated licenses and gitignores"
+          remote: "git@github.com:go-gitea/gitea.git"
+          ssh_key: ${{ secrets.DEPLOY_KEY }}