Update iPhone simulator

Author: muzahidul-opti

.github/workflows/unit_tests.yml

@@ -26,7 +26,7 @@ jobs:
           #   os_type: "iOS"
           #   simulator_xcode_version: 14.1
           - os: 16.2
-            device: "iPhone 12"
+            device: "iPhone 14"
             scheme: "OptimizelySwiftSDK-iOS"
             test_sdk: "iphonesimulator"
             platform: "iOS Simulator"