fix: use GitHub Actions compatible syntax for Gitea

.gitea/workflows/ci.yml

@@ -1,29 +1,32 @@
 name: CI
 
-on: [push, pull_request]
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
 
 jobs:
   test:
-    runs-on: gitea
+    runs-on: ubuntu-latest
     steps:
-      - name: Checkout
-        run: |
-          git clone https://${{ gitea.server }}/${{ gitea.repository }} .
-          git checkout ${{ gitea.sha }}
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
-      - name: Setup Python
-        run: |
-          python3 -m pip install --upgrade pip
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
 
       - name: Install dependencies
         run: |
+          python3 -m pip install --upgrade pip
           python3 -m pip install pytest ruff
           python3 -m pip install -e ".[dev]"
 
       - name: Run tests
-        run: |
-          python3 -m pytest tests/ -v --tb=short
+        run: python3 -m pytest tests/ -v --tb=short
 
-      - name: Lint
-        run: |
-          python3 -m ruff check i18n_key_sync/ tests/
+      - name: Run linting
+        run: python3 -m ruff check i18n_key_sync/ tests/