Impossible to use uppercase in variables names on /variables

[Voronenko]

Bug summary

As an prefect user, I should still be able to create variables on a UI under '/variables' that follow validation "Name may only contain letters, numbers, and underscores and may not begin or end with an underscore"

Expected scenario: I am able to create var name VARIABLE
Actual scenario: VARIABLE does not pass validation, while variable is.

Version info

Version:             2.20.14
API version:         0.8.4
Python version:      3.9.15
Git commit:          fb919c67
Built:               Mon, Nov 18, 2024 4:41 PM
OS/Arch:             linux/x86_64
Profile:             local
Server type:         server

Additional context

It was possible to create variable names in uppercase in previous versions at the beginning of the year