change python version in CI

Author: wbszhu

.github/workflows/python-package-conda.yml

@@ -11,10 +11,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.7
+    - name: Set up Python 3.9
       uses: actions/setup-python@v2
       with:
-        python-version: 3.7
+        python-version: 3.9
     - name: Install dependencies
       run: |
         sudo apt install libcurl4-openssl-dev