fix: simplify Gitea Actions workflow for better compatibility

.gitea/workflows/ci.yml

@@ -2,17 +2,15 @@ name: CI
 
 on:
   push:
-    branches:
+    branches: [main]
-      - main
   pull_request:
-    branches:
+    branches: [main]
-      - main
 
 jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout code
+      - name: Checkout
         run: |
           git clone https://${{ gitea.server }}/${{ gitea.repository }} .
           git checkout ${{ gitea.sha }}
@@ -21,14 +19,15 @@ jobs:
         run: |
           python3 -m pip install --upgrade pip
 
-      - name: Install dependencies
+      - name: Install
         run: |
+          python3 -m pip install pytest ruff
           python3 -m pip install -e ".[dev]"
 
-      - name: Run tests
+      - name: Test
         run: |
           python3 -m pytest tests/ -v --tb=short
 
-      - name: Run linting
+      - name: Lint
         run: |
           python3 -m ruff check i18n_key_sync/ tests/