Subviewport content cannot be rendered correctly on MacOS Chrome after exporting to html5

### Tested versions

- Reproducible in Godot 4.2.stable，4.3.stable

### System information

MacOS 14.1(M3 Pro) - Godot v4.3.stable - Chrome 128.0.6613.114 (arm 64)

### Issue description

When I use `Subviewport` to draw content, whether it is through `SubviewportContainer` or `ViewportTexture`, after exporting to HTML5, it cannot be rendered normally on **Chrome**.

some additional information:
- When using Godot4.2.stable to export **HTML5**, it cannot be rendered normally on **Safari 17.1** too.
- It seems that the two settings of *Render Target (Clear Mode, Update Mode)* on the Subviewport Inspect panel do not take effect.
- If MRP is uploaded to **itchio**, it will be rendered correctly on Chrome.
- It seems OK when html5 running on Chrome in **Windows**.

Scene Node Tree:

Inspect pannel:

Expect View:

View in Chrome:

### Steps to reproduce

Just add Subviewport to Scene and use Remote Debug - Run in Browser

### Minimal reproduction project (MRP)

[MRP.zip](https://github.com/user-attachments/files/16823782/MRP.zip)