Switch to Xcode 15 (with the iOS 16.4 Simulator for tests still) (#2113)

* Use Xcode 15 in GitHub actions.

Use iOS 16.4 simulators from Xcode 14 as iOS 17.0.1 simulators are **super** slow.

* Fix failing preview snapshots.

Snapshot fix.

* Improve setup

* Regenerate snapshots that had a conflict.

---------

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

.github/workflows/unit_tests.yml

@@ -38,6 +38,13 @@ jobs:
       - name: SwiftFormat
         run:
           swiftformat --lint .
+      
+      - name: Link to 16.4 Simulators
+        run: |
+          echo "Creating Runtimes folder if needed..."
+          sudo mkdir -p /Library/Developer/CoreSimulator/Profiles/Runtimes
+          echo "Creating symlink of the iOS 16.4 runtime..."
+          sudo ln -s /Applications/Xcode_14.3.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime /Library/Developer/CoreSimulator/Profiles/Runtimes/iOS\ 16.4.simruntime
 
       - name: Run tests
         run: bundle exec fastlane unit_tests