Update GitHub Actions to use macOS-14 (again).

See actions/runner-images#13046.

PiperOrigin-RevId: 836365578

Author: ericsalo

.github/workflows/test_upb.yml

@@ -162,13 +162,13 @@ jobs:
           # supported Python versions and assume this gives us sufficient test
           # coverage.
           - { os: ubuntu-latest, python-version: "3.9", architecture: x64, type: 'binary' }
-          - { os: macos-13, python-version: "3.9", architecture: x64, type: 'binary' }
+          - { os: macos-14, python-version: "3.9", architecture: arm64, type: 'binary' }
           - { os: ubuntu-latest, python-version: "3.13", architecture: x64, type: 'binary' }
-          - { os: macos-13, python-version: "3.13", architecture: x64, type: 'binary' }
+          - { os: macos-14, python-version: "3.13", architecture: arm64, type: 'binary' }
           - { os: ubuntu-latest, python-version: "3.9", architecture: x64, type: 'source'}
-          - { os: macos-13, python-version: "3.9", architecture: x64, type: 'source', continuous-only: true }
+          - { os: macos-14, python-version: "3.9", architecture: arm64, type: 'source', continuous-only: true }
           - { os: ubuntu-latest, python-version: "3.13", architecture: x64, type: 'source'}
-          - { os: macos-13, python-version: "3.13", architecture: x64, type: 'source', continuous-only: true }
+          - { os: macos-14, python-version: "3.13", architecture: arm64, type: 'source', continuous-only: true }
 
           # Windows uses the full API up until Python 3.10.
           - { os: windows-2022, python-version: "3.9", architecture: x86, type: 'binary', continuous-only: true }