Adding sdk_version to mac builds for dart-internal.

The osx_sdk version isn't getting propagated to the sub-builds,
so adding a property to pass it in.

Bug:b/232552448

Author: yusuf-goog

.ci.yaml

@@ -332,13 +332,17 @@ targets:
     timeout: 60
     properties:
       config_name: mac_android_aot_engine
+      $flutter/osx_sdk : >-
+        { "sdk_version": "14a5294e" }
 
   - name: Mac mac_host_engine
     recipe: engine_v2/engine_v2
     timeout: 60
     properties:
       release_build: "true"
       config_name: mac_host_engine
+      $flutter/osx_sdk : >-
+        { "sdk_version": "14a5294e" }
 
   - name: Mac Unopt
     recipe: engine/engine_unopt
@@ -432,6 +436,8 @@ targets:
     properties:
       release_build: "true"
       config_name: mac_ios_engine
+      $flutter/osx_sdk : >-
+        { "sdk_version": "14a5294e" }
       dependencies: >-
         [
           {"dependency": "jazzy", "version": "0.14.1"}
@@ -442,12 +448,16 @@ targets:
     timeout: 60
     properties:
       config_name: mac_ios_engine_profile
+      $flutter/osx_sdk : >-
+        { "sdk_version": "14a5294e" }
 
   - name:  Mac mac_ios_engine_release
     recipe: engine_v2/engine_v2
     timeout: 60
     properties:
       config_name: mac_ios_engine_release
+      $flutter/osx_sdk : >-
+        { "sdk_version": "14a5294e" }
 
   - name: Windows Android AOT Engine
     recipe: engine/engine