Set python version to 3.9.

Signed-off-by: Jay Zhang <[email protected]>

Author: fatcat-z

.github/workflows/main.yml

@@ -24,7 +24,7 @@ jobs:
       - id: prepare-variables
         name: Prepare Variables
         run: |
-          echo "##[set-output name=tf_version;]2.10.0"
+          echo "tf_version=2.10.0" >> $GITHUB_ENV
 
   call-setup-yml:
     needs: prepare-variables-job

.github/workflows/setup.yml

@@ -20,7 +20,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.x
+          python-version: 3.9
 
       - name: Install dependencies
         run: |