Revert "test macos-13-xlarge and ruby 2.7.8"

This reverts commit 688f49a819.

.github/actions/prepare-mobile-build/action.yaml

@@ -6,7 +6,7 @@ runs:
   steps:
     - uses: ruby/setup-ruby@9669f3ee51dc3f4eda8447ab696b3ab19a90d14b # v1.144.0
       with:
-        ruby-version: "2.7.8"
+        ruby-version: "2.7.7"
 
     - name: ci/setup-fastlane-dependencies
       shell: bash

.github/workflows/build-pr.yml

@@ -22,7 +22,7 @@ jobs:
         uses: ./.github/actions/test
 
   build-ios-pr:
-    runs-on: macos-13-xlarge
+    runs-on: macos-12-large
     if: ${{ github.event.label.name == 'Build Apps for PR' || github.event.label.name == 'Build App for iOS' }}
     needs:
       - test