Add auto-merge for weblate.

.github/workflows/weblate-merge.yml

@@ -0,0 +1,20 @@
+name: Merge Weblate translations
+
+on:
+  pull_request:
+    branches:
+      - weblate
+
+jobs:
+  merge:
+    runs-on: ubuntu-latest
+    steps:
+      # Run only if the PR is from Weblate
+      - name: Check if PR author is weblate
+        if: github.event.pull_request.user.login != 'weblate'
+        run: exit 78
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: AutoMerge Weblate translations
+        run: gh pr merge --auto --delete-branch --merge