fix: fix action

Author: okunator

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ jobs:
       fail-fast: true
       matrix:
         # python-version: ["3.7", "3.8", "3.9"]
-        python-version: ["3.8"]
+        python-version: ["3.9"]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps: