Fix Github actions python version

Author: youtux

.github/workflows/main.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", 3.10.0-rc.2]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
 
     steps:
     - uses: actions/checkout@v2