Bug 1680678 - Upgrade builds to Xcode 12.2 final's SDK. r=firefox-build-system-reviewers,dmajor

Differential Revision: https://phabricator.services.mozilla.com/D98712

taskcluster/ci/toolchain/misc.yml

@@ -354,7 +354,7 @@ macosx64-sdk-11.0:
     run:
         script: pack.sh
         arguments:
-            - /Applications/Xcode-12.2.Release.Candidate.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.0.sdk
+            - /Applications/Xcode-12.2.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.0.sdk
         toolchain-artifact: project/gecko/mac-sdk/MacOSX11.0.sdk.tar.zst
     # Expiry similar to that of fetches
     expires-after: 1000 years