Run tests on iOS 17 exclusively (#144022)

Almost all of our devicelab devices are on iOS 17 now, so let's use them exclusively so we can verify that tests pass consistently on iOS 17.

Fixes flutter/flutter#144020.

Author: vashworth

.ci.yaml

@@ -230,7 +230,7 @@ platform_properties:
         ]
       os: Mac-13
       cpu: x86
-      device_os: iOS-16|iOS-17
+      device_os: iOS-17
       $flutter/osx_sdk : >-
         {
           "sdk_version": "15a240d"
@@ -248,7 +248,7 @@ platform_properties:
         ]
       os: Mac-13
       cpu: x86
-      device_os: iOS-16|iOS-17
+      device_os: iOS-17
       $flutter/osx_sdk : >-
         {
           "sdk_version": "15a240d"
@@ -266,7 +266,7 @@ platform_properties:
         ]
       os: Mac-13
       cpu: arm64
-      device_os: iOS-16|iOS-17
+      device_os: iOS-17
       $flutter/osx_sdk : >-
         {
           "sdk_version": "15a240d"
@@ -4769,7 +4769,7 @@ targets:
         ["devicelab", "ios", "mac"]
       task_name: flutter_gallery__transition_perf_e2e_ios
       drone_dimensions: >
-        ["device_os=iOS-16|iOS-17","os=Mac-13", "cpu=x86"]
+        ["device_os=iOS-17","os=Mac-13", "cpu=x86"]
 
   - name: Mac_ios animated_blur_backdrop_filter_perf_ios__timeline_summary
     recipe: devicelab/devicelab_drone