fix: run iOS and Android builds on studio runner

The mini runner has network issues reaching MinIO.
Route all mobile builds to studio.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: pythoninthegrass

.github/workflows/build-android-app.yml

@@ -29,7 +29,7 @@ concurrency:
 
 jobs:
   build:
-    runs-on: self-hosted
+    runs-on: [self-hosted, studio]
     env:
       BUNDLE_FROZEN: "true"
       RUBYOPT: "-W0"

.github/workflows/build-ios-app.yml

@@ -29,7 +29,7 @@ concurrency:
 
 jobs:
   build:
-    runs-on: self-hosted
+    runs-on: [self-hosted, studio]
     env:
       BUNDLE_FROZEN: "true"
       RUBYOPT: "-W0"