[BUGFIX] Remove old Stage editor keybind functionality

[sphis-Sinco]

Does this PR close any issues? If so, link them below.

#3850

Briefly describe the issue(s) fixed.

• The Stage Editor keybind functionality has been removed as to fix an issue where the old stage editor would be enabled and basically break gameplay (even when resetting the song) until you leave to the menu and reenter the song.

Include any relevant screenshots or videos.

Before:

bugfix-oldstageeditor-before.mp4

After:

bugfix-oldstageeditor-after.mp4

[Hundrec]

Thanks for addressing this issue! I can't verify the functionality of this PR, but I do have a few tips for your future PRs:

If screenshots or videos aren't the best way to convey the function of your PR, please only include a description of the function. Many PRs can be more easily understood with just a clear description!

For any videos you do choose to include, please trim them to the relevant content and necessary context. It'll help us understand what you changed!

Thanks again for submitting PRs!

[sphis-Sinco]

Thanks for addressing this issue! I can't verify the functionality of this PR, but I do have a few tips for your future PRs:

If screenshots or videos aren't the best way to convey the function of your PR, please only include a description of the function. Many PRs can be more easily understood with just a clear description!

For any videos you do choose to include, please trim them to the relevant content and necessary context. It'll help us understand what you changed!

Thanks again for submitting PRs!

No problem!