add-GHActions-timeout-for-smoke-tests (#1743)

We need to explicitly set timeout for smoke tests, since GH Action's default is 360 mins (6 hours 😱 )

https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idtimeout-minutes

Thank you!

.github/workflows/push_tests.yml

@@ -73,6 +73,7 @@ jobs:
 
   smoke-tests:
     runs-on: macos-latest
+    timeout-minutes: 20
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python 3.7
@@ -102,6 +103,7 @@ jobs:
 
   smoke-tests-annotations:
     runs-on: ubuntu-latest
+    timeout-minutes: 20
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python 3.7