Use MacOS 11, xcode 13.2.1 for SDK 15.2 xbuild

azure-pipelines.yml

@@ -224,10 +224,10 @@ jobs:
 
 - job: OSX_IOS_ARMV8
   pool:
-     vmImage: 'macOS-10.15'
+     vmImage: 'macOS-11'
   variables:
-     CC: /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
-     CFLAGS: -O2 -Wno-macro-redefined -isysroot /Applications/Xcode_12.4.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.2.sdk -arch arm64 -miphoneos-version-min=10.0
+     CC: /Applications/Xcode_13.2.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
+     CFLAGS: -O2 -Wno-macro-redefined -isysroot /Applications/Xcode_13.2.1.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.2.sdk -arch arm64 -miphoneos-version-min=10.0
   steps:
   - script: |
      make TARGET=ARMV8 DYNAMIC_ARCH=1 NUM_THREADS=32 HOSTCC=clang NOFORTRAN=1