Changing syntax highlight setting does not update text highlighting

[Lunarexxy]

Tested versions

Reproducible in v4.4.dev6.official [1f47e4c]
Reproducible in v4.4.dev2.official [97ef3c8]
Not reproducible in v4.4.dev1.official [28a72fa]
Not reproducible in Godot 4.3

System information

Godot v4.4.dev2 - Windows 10.0.19045 - OpenGL 3 (Compatibility) - NVIDIA GeForce RTX 2060 (NVIDIA; 32.0.15.6590) - AMD Ryzen 7 4800H with Radeon Graphics (16 Threads)

Issue description

A very minor regression. When a text or script file is open, changing the syntax highlighting setting under Edit -> Syntax Highlighter -> [any setting] does not cause the text to use the new syntax highlighting, until some change in the text is made or the file is closed and reopened.

May be considered a duplicate of #98367, though that one is related to changing editor theme, while this one is about changing a script editor setting. Feel free to close if tracking one issue is easier.

Possibly caused by #92865.

Steps to reproduce

Create a text or script file and write something in it.
Open it in the built-in script editor.
Change Edit -> Syntax Highlighter to any option.
Notice no immediate change to syntax highlighting.
(if you edit the text, it will properly update)

Minimal reproduction project (MRP)

This project includes two text files, one .txt and one .gd, with mostly identical contents. File type doesn't seem to matter, though.

syntax_highlight_bug.zip

[Calinou]

I can confirm this on 4.4.dev 9e60984.