xcodebuild -showsdks -json is returning the same sdkVersion for different sdkPaths on > Xcode 14

  {
    "canonicalName" : "macosx13.0",
...
    "sdkPath" : "/Users/m/Applications/Xcode-14-1_beta3.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.sdk",
    "sdkVersion" : "13.0"
  },
  {
    "canonicalName" : "macosx13.0",
...
    "sdkPath" : "/Users/m/Applications/Xcode-14-1_beta3.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.0.sdk",
    "sdkVersion" : "13.0"
  },

The order it's returning these isn't stable, so it keeps swapping which path is listed last on different runs which is causing -isysroot to be different between ninja runs, which is unnecessaryly dirtying and causing huge recompiles.

Sort the SDKs returned by xcodebuild -showsdks so that duplicated sdkVersions mapped to different paths always chooses the same path between runs.

Fixes flutter/flutter#112928

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