Revert zip builds to macos-13 (#13562)

Author: paulb777

.github/workflows/zip.yml

@@ -30,7 +30,7 @@ jobs:
   package-release:
     # Don't run on private repo.
     if: (github.repository == 'Firebase/firebase-ios-sdk' && github.event_name == 'schedule') || github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch'
-    runs-on: macos-14
+    runs-on: macos-13
     steps:
     - uses: actions/checkout@v4
     - uses: mikehardy/buildcache-action@c87cea0ccd718971d6cc39e672c4f26815b6c126
@@ -58,7 +58,7 @@ jobs:
   build:
     # Don't run on private repo unless it is a PR.
     if: (github.repository == 'Firebase/firebase-ios-sdk' && github.event_name == 'schedule') || github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch'
-    runs-on: macos-14
+    runs-on: macos-13
     steps:
     - uses: actions/checkout@v4
     - name: Xcode 15.2
@@ -75,7 +75,7 @@ jobs:
     strategy:
       matrix:
         linking_type: [static, dynamic]
-    runs-on: macos-14
+    runs-on: macos-13
     steps:
     - uses: actions/checkout@v4
     - uses: mikehardy/buildcache-action@c87cea0ccd718971d6cc39e672c4f26815b6c126