Build macOS CLI artefacts for arm64 (#352)

Summary:
As noted on #345 (comment), that PR did not update the CLI artefacts to build for arm64.

I think there’s an opportunity to reduce the amount of separate builds and package both the runtime package and CLI from the same artefacts while also reducing build time, but for now I’d like to ensure the CLI tools at least also come with arm64 slices.

Pull Request resolved: #352

Test Plan:
Tested on a DTK machine:

```
$ ditto --arch arm64 package/osx-bin/hermes package/osx-bin/hermes-arm64
$ file package/osx-bin/hermes-arm64
package/osx-bin/hermes-arm64: Mach-O 64-bit executable arm64
$ echo "'use strict'; function hello() { print('Hello World'); } hello();" | ./package/osx-bin/hermes-arm64
>> Hello World
undefined
>>
```

Reviewed By: Huxpro

Differential Revision: D23709228

Pulled By: tmikov

fbshipit-source-id: 881deab450d4f9005cdc2ce9ce292b1ba46bd455

.circleci/config.yml

@@ -196,7 +196,7 @@ jobs:
 
   macos:
     macos:
-      xcode: "10.0.0"
+      xcode: "12.0.0"
     environment:
       - HERMES_WS_DIR: /tmp/hermes
       - TERM: dumb
@@ -219,7 +219,7 @@ jobs:
           name: Build Hermes for macOS
           command: |
             cd "$HERMES_WS_DIR"
-            hermes/utils/build/configure.py --distribute --cmake-flags='-DHERMES_BUILD_APPLE_FRAMEWORK:BOOLEAN=false'
+            hermes/utils/build/configure.py --distribute --cmake-flags='-DHERMES_BUILD_APPLE_FRAMEWORK:BOOLEAN=false -DCMAKE_OSX_ARCHITECTURES:STRING=x86_64;arm64 -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.13'
             cmake --build ./build_release --target github-cli-release
       - run:
           name: Copy artifacts