Merged PR 533872: Fix redis-osx nuget dependency

In public builds, skip downloading the `Redis-osx-x64` nuget on all platforms.

This will create an empty stub for this package, meaning we won't be able to run any Redis unit tests in public builds (which is fine)

config.dsc

@@ -216,7 +216,9 @@ config({
                 { id: "System.Interactive.Async", version: "3.1.1" },
                 { id: "TransientFaultHandling.Core", version: "5.1.1209.1" },
                 { id: "Redis-64", version: "3.0.503", osSkip: [ "macOS" ] },
-                { id: "Redis-osx-x64", version: "1.0.0", osSkip: [ "win" ] },
+                { id: "Redis-osx-x64", version: "1.0.0", osSkip: importFile(f`config.microsoftInternal.dsc`).isMicrosoftInternal
+                    ? [ "win" ]
+                    : [ "win", "macOS" ] },
 
                 // Testing
                 { id: "System.Security.Cryptography.ProtectedData", version: "4.4.0"},