UI test cleanup (#2598)

* Stop running the UI tests on the double localized pseudolanguage

* Fix UI tests signalling comms problem because the json key ordering wasn't defined and the messages wouldn't match.

* Remove UI tests that are now the same as preview tests (i.e. non flow based, only screen based), fixed the rest so they run on iOS 17.2, the iPhone 15 and iPad 10th gen simulators.

* Remove unnecessary gitignore instructions, change UI test snapshot naming convention to be more similar to the unit test ones

* Enable derived data and spm checkout caching for UI tests

* Switch UI tests back to the perf-only runner, moved the integration tests to the iPhone 15 Pro simulator.

* Address PR comments

.github/workflows/ui_tests.yml

@@ -13,16 +13,20 @@ on:
 jobs:
   tests:
     name: Tests
-    runs-on: macos-14
+    runs-on: perf-only
 
     concurrency:
-      # When running on develop, use the sha to allow all runs of this workflow to run concurrently.
-      # Otherwise only allow a single run of this workflow on each branch, automatically cancelling older runs.
-      group: ${{ github.ref == 'refs/heads/develop' && format('ui-tests-develop-{0}', github.sha) || format('ui-tests-{0}', github.ref) }}
+      # Only allow a single run of this workflow on each branch, automatically cancelling older runs.
+      group: ${{ format('ui-tests-{0}', github.ref) }}
       cancel-in-progress: true
 
     steps:
-      - uses: nschloe/action-cached-lfs-checkout@v1.2.1
+      - uses: nschloe/action-cached-lfs-checkout@v1
+
+      - uses: irgaly/xcode-cache@v1
+        with:
+          key: xcode-cache-deriveddata-${{ github.workflow }}-${{ github.ref }}
+          restore-keys: xcode-cache-deriveddata-${{ github.workflow }}-${{ github.ref }}
 
       - uses: actions/cache@v3
         with: