The `NOTIFICATION_WM_SIZE_CHANGED` is not propagated into children

### Tested versions

4.4.stable

### System information

Godot v4.4.stable - Windows 10 (build 19045) - Multi-window, 2 monitors - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 Ti (NVIDIA; 32.0.15.6636) - Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (8 threads)

### Issue description

Currently Godot propagates Window notifications into its children, such as NOTIFICATION_WM_MOUSE_ENTER, NOTIFICATION_WM_MOUSE_EXIT, etc.
However, the only one that's not propagating is NOTIFICATION_WM_SIZE_CHANGED.

### Steps to reproduce

N/A

### Minimal reproduction project (MRP)

N/A

Start by locating where NOTIFICATION_WM_MOUSE_ENTER and related window notifications are propagated to children, then compare that path with NOTIFICATION_WM_SIZE_CHANGED. Confirm the expected behavior across child windows and verify that the size-change notification reaches them without breaking existing notification handling.

Written by the indexing model from the issue text.