Revert "Update Xcode version to 13a233 (#98144)" (#98263)

This reverts commit 84fcb158.

.ci.yaml

@@ -63,10 +63,10 @@ platform_properties:
         ]
       dependencies: >-
         []
-      os: Mac-12
+      os: Mac-10.15
       device_type: none
       mac_model: Macmini8,1
-      xcode: 13a233
+      xcode: 12c33
   mac_android:
     properties:
       caches: >-
@@ -85,7 +85,7 @@ platform_properties:
           {"dependency": "chrome_and_driver", "version": "version:84"},
           {"dependency": "open_jdk"}
         ]
-      os: Mac-12
+      os: Mac-12.0
       device_os: N
   mac_ios:
     properties:
@@ -106,7 +106,7 @@ platform_properties:
           {"dependency": "gems"},
           {"dependency": "ios_signing"}
         ]
-      os: Mac-12
+      os: Mac-12.0
       device_os: iOS-15.1
       xcode: 13a233
   windows: