maint: update main Python version (#349)

Author: RobPasMue

.github/workflows/ci_cd.yml

@@ -9,7 +9,7 @@ on:
       - main
 
 env:
-  MAIN_PYTHON_VERSION: '3.9'
+  MAIN_PYTHON_VERSION: '3.10'
   PACKAGE_NAME: 'ansys-dyna-core'
   PACKAGE_NAMESPACE: 'ansys.dyna.core'
   DOCUMENTATION_CNAME: "dyna.docs.pyansys.com"