Fix dmg build (#929)

Summary:
Still had the old paths referenced.
Pull Request resolved: https://github.com/facebook/flipper/pull/929

Test Plan: Next release, I guess?

Reviewed By: nikoant

Differential Revision: D20669327

Pulled By: passy

fbshipit-source-id: e268259065df5a48336ec09b81776771e1124fd0

.github/workflows/dmg-release.yml

@@ -8,6 +8,8 @@ jobs:
   build:
 
     runs-on: macos-latest
+    env:
+      desktop-directory: ./desktop
 
     steps:
     - uses: actions/checkout@v1
@@ -16,8 +18,10 @@ jobs:
         node-version: '12.x'
     - name: Install
       run: yarn
+      working-directory: ${{env.desktop-directory}}
     - name: Build
       run: yarn build --mac --mac-dmg
+      working-directory: ${{env.desktop-directory}}
     - name: Upload
       uses: skx/github-action-publish-binaries@master
       env:

.github/workflows/nodejs.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     env:
-      desktop-directory: ./desktop    
+      desktop-directory: ./desktop
 
     strategy:
       matrix: