modify python version for weekly test

Signed-off-by: Yiheng Wang <[email protected]>

.github/workflows/weekly-tests-cpu.yml

@@ -6,16 +6,19 @@ on:
   - cron: "0 5 * * 0"  # 5:00, every Sunday
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
+  # Trigger the workflow on pull request activity
+  pull_request:
+    branches: [ dev ]
 
 jobs:
   get-list:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.8
+    - name: Set up Python 3.9
       uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: cache weekly timestamp
       id: pip-cache
       run: |
@@ -47,10 +50,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.8
+    - name: Set up Python 3.9
       uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: cache weekly timestamp
       id: pip-cache
       run: |