fix(ci): keep the workflow and runner compatible with Gitea 1.20

github.* is the documented context alias and exists in 1.20; gitea.* came
later. The runner is pinned instead of :latest — the registration protocol
moves with the server, and a newer runner refuses to register against an older
Gitea.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitea/workflows/tests.yml

@@ -55,7 +55,7 @@ jobs:
   release:
     # Only a green run produces the tag the console offers as an update.
     needs: [pest, assets]
-    if: gitea.ref == 'refs/heads/main'
+    if: github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

docker-compose.yml

@@ -96,7 +96,7 @@ services:
   # Gitea Actions runner. Opt-in via profile, because a development machine does
   # not need to burn cycles on CI:  docker compose --profile ci up -d runner
   runner:
-    image: gitea/act_runner:latest
+    image: gitea/act_runner:${GITEA_RUNNER_VERSION:-0.2.6}
     restart: unless-stopped
     profiles: [ci]
     environment: