Update build_pkg_alpha_xcode_beta.yml (#242)

Author: jordywitteman

.github/workflows/build_pkg_alpha_xcode_beta.yml

@@ -4,7 +4,7 @@ on: [workflow_dispatch]
 
 jobs:
   build_with_signing:
-    runs-on: macos-15
+    runs-on: [self-hosted, macOS]
     environment: production
 
     steps: