### Godot version

v4.2.dev4.official [549fcce5f]

### System information

Ubuntu 20.04 LTS

### Issue description

See title.

### Steps to reproduce

1. Create a new project
2. Create a csv file that includes the following
```
key,ar
key,placeholder
```
3. Add the generated `.translation` file to Project -> Project Settings... -> Localization
4. In Project -> Project Settings... -> Internationalization -> Locale, set `Test` to `ar`
5. Add a `LineEdit` node and type `-=[]{}`
6. Run the project, and notice that the text is on the right side, but the symbols are incorrectly in LTR (`-=[]{}`).  Correct output is `{}[]=-`
7. Back in the editor, add a single Arabic letter (any will do), and notice that `LineEdit` immediately (and correctly) flips the symbols, and the newly-added Arabic letter, to RTL.

**Notes**
- Identical behavior is seen with `TextEdit`.
- The purpose of steps 2-4 are to simulate an Arabic environment when the project is run, despite `OS.get_locale() == "en"` (or your system's current language).

### Minimal reproduction project

[rtlsymbols.zip](https://github.com/godotengine/godot/files/12525509/rtlsymbols.zip)
ERR_FAIL_COND_V(!_ensure_cache_for_size(p_font_data, p_size), false);
	int32_t glyph_index = p_glyph & 0xffffff; 
	FontForSizeAdvanced *fd = p_font_data->cache[p_size];
	if (fd->glyph_map.has(p_glyph)) {
		return fd->glyph_map[p_glyph].found;
	}
	if (glyph_index  
		fd->glyph_map[p_glyph] = FontGlyph();
		return true;
	}
#ifdef MODULE_FREETYPE_ENABLED
	FontGlyph gl;
	if (fd->face) {
		FT_Int32 flags = FT_LOAD_DEFAULT;
		bool outline = p_size.y > 0;
		switch (p_font_data->hinting) {
			case TextServer::HINTING_NONE:
				flags |= FT_LOAD_NO_HINTING;
				
			case TextServer::HINTING_LIGHT:
				flags |= FT_LOAD_TARGET_LIGHT;
				
			default: