Editor plugin hooks return immediatly ignoring `await`

Tested versions

4.4.dev

System information

Windows 11 - Vulkan (Forward+)

Issue description

Coroutines don't work in EditorPlugin hooks like:

@tool
extends EditorPlugin

# The project runs immediately and "finished build check" prints after it
func _build() -> bool:
	print("awaiting _build")
	await get_tree().create_timer(3).timeout
	print("finished _build")
	return false

Other hooks used together with EditorPlugin like EditorExportPlugin._customize_resource also return immediately ignoring await. This makes it impossible to customize resources that depend on threaded features like NavigationMesh baking or the render thread.

Steps to reproduce

Run MRP. Build should not return because _build() in "res://addons/plugin/plugin.gd" returns false.
But it runs anyway and "Finished Build" is printed 3 seconds later.

Export MRP. It should print "finished _customize_resource" after exporting.
But it exports immediately and the message is printed 3 seconds later.

Minimal reproduction project (MRP)

plugin-await-issue.zip

Start by running the linked minimal reproduction project and inspect res://addons/plugin/plugin.gd, focusing on the _build() and _customize_resource hooks. Confirm the immediate-return behavior during Build and Export, then trace the corresponding EditorPlugin and EditorExportPlugin hook handling. Done means awaited hooks delay completion and the documented output order matches the issue.