DeprecationWarning: Implicit Radix Themes enablement has been deprecated in version 0.9.0.

[masenf]

Describe the bug
The default template (and other templates) use radix themes, but do not list the radix themes plugin in the rxconfig.py file, so this warning is raised.

To Reproduce

reflex init
reflex run

Expected behavior
A new app should not have deprecation warnings.

Specifics (please complete the following information):

• Python Version: 3.10+
• Reflex Version: 0.9.1+

[linear]

ENG-9483