Local leader is not accessible in custom evil states

### What did you expect to happen?

When binding `doom/leader` for a new evil state, the local leader commands should also be accessible.

### What actually happened?

Local leader commands are not accessible.

### Describe your attempts to resolve the issue

None, as it appears to be a hardcoded value in doom-core here:
https://github.com/hlissner/doom-emacs/blob/develop/core/core-keybinds.el#L177

Possibly related issue: https://github.com/hlissner/doom-emacs/issues/1364

### Steps to reproduce

1. Create a new evil state and bind `doom/leader` like so:
```
(evil-define-state foo "!")
(setq doom-evil-state-alist `((?f . foo) . ,doom-evil-state-alist))
(map! :map general-override-mode-map
:f "SPC" 'doom/leader)
(evil-foo-state)
```
2. Type `SPC m`

### System Information

https://pastebin.com/cSdb8EC0