CI: pin builds to the desktop runner

The RN/NDK build exhausted the 8GB VPS (whole docker stack went down
2026-08-08); marcusDesktop (32 threads) now handles these, and jobs
queue while it is offline.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -6,7 +6,9 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    # RN/NDK builds need ~6GB and once took down the 8GB VPS — desktop runner only.
+    # Jobs queue while the desktop is offline.
+    runs-on: desktop
     container:
       image: eclipse-temurin:21-jdk
     steps: