remove the osx14 update

Author: marcpopMSFT

src/Tests/Microsoft.NET.TestFramework/ToolsetInfo.cs

@@ -22,8 +22,8 @@ public class ToolsetInfo
 
         public const string LatestWinRuntimeIdentifier = "win10";
         public const string LatestLinuxRuntimeIdentifier = "ubuntu.20.04";
-        public const string LatestMacRuntimeIdentifier = "osx.14";
-        public const string LatestRuntimeIdentifiers = $"{LatestWinRuntimeIdentifier}-x64;{LatestWinRuntimeIdentifier}-x86;osx.10.10-x64;osx.10.11-x64;osx.10.12-x64;osx.10.14-x64;osx.12-x64;{LatestMacRuntimeIdentifier}-x64;ubuntu.14.04-x64;ubuntu.16.04-x64;ubuntu.16.10-x64;ubuntu.18.04-x64;{LatestLinuxRuntimeIdentifier}-x64;centos.7-x64;rhel.7.2-x64;debian.8-x64;fedora.24-x64;opensuse.42.1-x64;linux-musl-x64";
+        public const string LatestMacRuntimeIdentifier = "osx.12";
+        public const string LatestRuntimeIdentifiers = $"{LatestWinRuntimeIdentifier}-x64;{LatestWinRuntimeIdentifier}-x86;osx.10.10-x64;osx.10.11-x64;osx.10.12-x64;osx.10.14-x64;{LatestMacRuntimeIdentifier}-x64;ubuntu.14.04-x64;ubuntu.16.04-x64;ubuntu.16.10-x64;ubuntu.18.04-x64;{LatestLinuxRuntimeIdentifier}-x64;centos.7-x64;rhel.7.2-x64;debian.8-x64;fedora.24-x64;opensuse.42.1-x64;linux-musl-x64";
 
         public string DotNetRoot { get; }
         public string DotNetHostPath { get; }