ci: use self-hosted runner and simplify python steps

.gitea/workflows/ci.yml

@@ -7,24 +7,25 @@ on:
   pull_request:
     branches:
       - main
+  workflow_dispatch:
 
 jobs:
   lint-and-compile:
-    runs-on: ubuntu-latest
+    # Prefer local Gitea runner labels to avoid pending/cancelled jobs.
+    runs-on: self-hosted
+    timeout-minutes: 15
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: "3.11"
+      - name: Show environment
+        run: |
+          pwd
+          ls -la
+          python3 --version
 
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip
-          pip install -r requirements.txt
+          python3 -m pip install --upgrade pip
+          python3 -m pip install -r requirements.txt
 
       - name: Compile Python files
         run: |
-          python -m py_compile app/*.py
+          python3 -m py_compile app/*.py