[SW-562] update sphinx workflow (#97)

minor update to sphinx workflow on github.

Author: jcao-bdai

.github/workflows/master.yml

@@ -63,7 +63,4 @@ jobs:
     # If the above worked:
     # Build docs and upload to GH Pages
     needs: unittest
-    runs-on: ubuntu-latest
-    steps:
-      - uses: ./.github/workflows/sphinx.yml
-        if: ${{ github.event_name != 'pull_request' }}
+    uses: ./.github/workflows/sphinx.yml

.github/workflows/sphinx.yml

@@ -6,6 +6,7 @@ on:
 jobs:
   sphinx:
     runs-on: ubuntu-latest
+    if: ${{ github.event_name != 'pull_request' }}
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python 3.7