Fix vertical alignment of editor version LinkButton in the bottom panel

[passivestar]

Closes #88196

[passivestar]

Removed the box container

Screen.Recording.mp4

[passivestar]

Took another look to make sure this doesn't break anything. Can't find anything trying to reference that box container indirectly, from what I understand it's not common in engine code to do that and it would have been made public if it was of any interest outside of class. Seems safe to remove

So I think this is ready for review

If relevant here's a theme that sets Button's top and bottom margins to abnormally high values for testing (it will make the bottom panel higher):

[gd_resource type="Theme" load_steps=2 format=3 uid="uid://dup750ctlh6cd"]

[sub_resource type="StyleBoxEmpty" id="StyleBoxEmpty_s86oa"]
content_margin_top = 40.0
content_margin_bottom = 40.0

[resource]
Button/styles/normal = SubResource("StyleBoxEmpty_s86oa")

[akien-mga]

Looks good to me. Needs a rebase.

[akien-mga]

Thanks!