Bump CI Xcode and iOS Version to 14.5

Summary:
Similar to https://github.com/facebook/react-native/pull/31554 (D28547839 (b2ec89fdfc))

This diff bumps Xcode to 12.5.0 both internally, and in Circle CI.

According to [Circle CI docs](https://circleci.com/docs/2.0/testing-ios/#supported-xcode-versions), their environments support Xcode 12.5.0.

Changelog: [Internal]

Reviewed By: yungsters

Differential Revision: D28952323

fbshipit-source-id: e15871d72094cfbcf9edb633586b37042e79901a

.circleci/config.yml

@@ -52,7 +52,7 @@ executors:
   reactnativeios:
     <<: *defaults
     macos:
-      xcode: &_XCODE_VERSION "12.4.0"
+      xcode: &_XCODE_VERSION "12.5.0"
 
 # -------------------------
 #        COMMANDS

scripts/.tests.env

@@ -24,7 +24,7 @@ export AVD_ABI=x86
 export ANDROID_DISABLE_AVD_TESTS=1
 
 ## IOS ##
-export IOS_TARGET_OS="14.4"
+export IOS_TARGET_OS="14.5"
 export IOS_DEVICE="iPhone 8"
 export SDK_IOS="iphonesimulator"