### Godot version

4.1.dev (dc625bcbfc5b587ba8867481ee7a1f6a567c25d0)

### System information

Mageia 9, Linux

### Issue description

When importing a project in current `master`, the following error is raised for each asset that gets imported:
```
Attempting to parent and popup a dialog that already has a parent.
```

It seems to be raised once per asset, caused by the progress dialog.

CC @bruvzg

### Steps to reproduce

- Import a new project in Godot that contains importable assets, e.g. https://github.com/RPicster/godot4-demo-desert-light

### Minimal reproduction project

See above.
ERR_MAIN_THREAD_GUARD;
	if (exclusive == p_exclusive) {
		return;
	}
	exclusive = p_exclusive;
	if (!embedder && window_id != DisplayServer::INVALID_WINDOW_ID) {
		if (is_in_edited_scene_root()) {
			DisplayServer::get_singleton()->window_set_exclusive(window_id, false);
		} else {
			DisplayServer::get_singleton()->window_set_exclusive(window_id, exclusive);
		}
	}
	if (transient_parent) {
		if (p_exclusive && is_inside_tree() && is_visible()) {
			ERR_FAIL_COND_MSG(transient_parent->exclusive_child && transient_parent->exclusive_child != this, "Transient parent has another exclusive child.");
			if (!is_in_edited_scene_root()) {
				transient_parent->exclusive_child = this;
			}
		} else {
			if (transient_parent->exclusive_child == this) {
				transient_parent->exclusive_child = nullptr;
			}
		}
	}
}
bool Window::is_exclusive() const {
	ERR_READ_THREAD_GUARD_V(false);
	return exclusive;
}
bool Window::is_visible() const {