fix(ci): align runs-on labels with gitea/act_runner defaults — advertise ubuntu-22.04 instead of self-hosted

.gitea/workflows/ci.yml

@@ -13,7 +13,7 @@ concurrency:
 jobs:
   ruff:
     name: lint (ruff)
-    runs-on: self-hosted
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -33,7 +33,7 @@ jobs:
 
   pytest:
     name: pytest (py${{ matrix.python-version }})
-    runs-on: self-hosted
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
       matrix: