Avoid accessing the theme too early in EditorRunBar

[YuriSizov]

Fixes #76509.

I missed it initially because it happens before the editor output can display those errors, so you can only see it in the terminal during the startup. Perhaps we could somehow store those messages, and then print them once the editor output is ready?

[akien-mga]

Thanks!

[Araraura]

I'm still experiencing #76509 when opening any project in 4.1.1-stable. Not sure what might be causing this, I'm not using any undocked windows either. The line where the warning is outputted is different from the original issue:

scene/gui/control.cpp:2522 - Attempting to access theme items too early; prefer NOTIFICATION_POSTINITIALIZE and NOTIFICATION_THEME_CHANGED

And here's a project it's occurring for me on
Kenney2023Game.zip

[YuriSizov]

@Araraura Please open an issue. The error is generic and is not related to a specific control, each case needs to be investigated individually. When you create an issue, please specify what steps do you take for the error to appear. For example, which parts of the editor do you interact with and how right before the message appears.