Run CI with Xcode 26.1 RC (#4672)

* Use Xcode 26.1 RC on CI

* regenerated previews with 26.1

* ui tests

* fix

* fix some iPad tests rendering

* remove useless fastlane line

---------

Co-authored-by: Doug <douglase@element.io>

.github/workflows/ui_tests.yml

@@ -13,7 +13,7 @@ on:
 jobs:
   tests:
     name: Tests
-    runs-on: macos-15
+    runs-on: macos-26
     timeout-minutes: 90
     strategy:
       fail-fast: false

.github/workflows/unit_tests.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   tests:
     name: Tests
-    runs-on: macos-15
+    runs-on: macos-26
     timeout-minutes: 60
 
     concurrency:

.github/workflows/unit_tests_enterprise.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   tests:
     name: Tests (Enterprise)
-    runs-on: macos-15
+    runs-on: macos-26
     timeout-minutes: 45
     
     # Skip in forks