Changed<GlobalTransform> is triggered on each frame for UI nodes

[oceantume]

Bevy version

0.6.1

What you did

Run the following bevy app

use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_startup_system(setup)
        .add_system(do_something_with_node_transform)
        .run();
}

#[derive(Component)]
struct MyNode;

fn setup(mut commands: Commands) {
    commands.spawn_bundle(UiCameraBundle::default());

    commands
        .spawn_bundle(NodeBundle {
            style: Style {
                size: Size::new(Val::Px(150.), Val::Px(60.)),
                margin: Rect::all(Val::Auto),
                ..Default::default()
            },
            color: Color::BLACK.into(),
            ..Default::default()
        });
}

fn do_something_with_node_transform(
    query: Query<&GlobalTransform, Changed<GlobalTransform>>
) {
    for transform in query.iter() {
        bevy::log::info!("Transform changed: {transform:?}");
    }
}

What you expected to happen

The print should only happen when the value of GlobalTransform is actually changed.

What actually happened

A line is printed on every frame, even when the value of GlobalTransform doesn't change.

Additional information

The issue is present when watching both Transform and GlobalTransform.

This is basically the same issue as #3784 but for the GlobalTransform component instead of Node. The fix will be very similar.