test(ci): use macos-14 for iOS build

was `macOS-latest` and somehow this resulted in macos-12 image
being used, which did not work well

Note that the all-lowercase `macos-latest` still resulted in macos-12
runner despite the github documentation specifying that macos-latest
should be macos-14 at this point

See #506

.github/workflows/ci.yml

@@ -75,7 +75,7 @@ jobs:
       - name: Build android example app
         run: yarn example:install && yarn example:devcopy && yarn example:install && cd RNFBSDKExample && cd android && ./gradlew assembleDebug
   ios-build:
-    runs-on: macOS-latest
+    runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
       - name: Setup Node