Update python version.

Author: VJalili

.github/workflows/pytest.yaml

@@ -12,10 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python 3.8
+    - name: Set up Python 3.13
       uses: actions/setup-python@v3
       with:
-        python-version: 3.8
+        python-version: 3.13
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip