downgrade to v3

Author: auvipy

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
 
         steps:
             -   uses: actions/checkout@v3
-            -   uses: actions/setup-python@v4
+            -   uses: actions/setup-python@v3
                 with:
                     python-version: ${{ matrix.python-version }}
             -   run: pip install tox