add env on ci yml

.github/workflows/ci.yml

@@ -5,21 +5,22 @@ on:
   pull_request:
     branches: [main]
 
-variables:
-  python-version: "3.10"
 
 jobs:
   build:
     runs-on: ubuntu-latest
 
+    env:
+      python-version: "3.10"
+
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v2
 
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: ${{ variables.python-version }}
+          python-version: ${{ env.python-version }}
 
       - name: Install Dependencies
         run: pip install -r requirements.txt