Update Python 3.10 CI version

Author: duckontheweb

.github/workflows/continuous-integration.yml

@@ -23,7 +23,7 @@ jobs:
           - "3.7"
           - "3.8"
           - "3.9"
-          - "3.10.0-beta.3"
+          - "3.10.0-rc.1"
         os:
           - ubuntu-latest
           - windows-latest