### 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)
flags |= FT_LOAD_TARGET_NORMAL;
				
		}
		if (p_font_data->force_autohinter) {
			flags |= FT_LOAD_FORCE_AUTOHINT;
		}
		if (outline) {
			flags |= FT_LOAD_NO_BITMAP;
		} else if (FT_HAS_COLOR(fd->face)) {
			flags |= FT_LOAD_COLOR;
		}
		FT_Fixed v, h;
		FT_Get_Advance(fd->face, glyph_index, flags, &h);
		FT_Get_Advance(fd->face, glyph_index, flags | FT_LOAD_VERTICAL_LAYOUT, &v);
		int error = FT_Load_Glyph(fd->face, glyph_index, flags);
		if (error) {
			fd->glyph_map[p_glyph] = FontGlyph();
			return false;
		}
		if (!p_font_data->msdf) {
			if ((p_font_data->subpixel_positioning == SUBPIXEL_POSITIONING_ONE_QUARTER) || (p_font_data->subpixel_positioning == SUBPIXEL_POSITIONING_AUTO && p_size.x <= SUBPIXEL_POSITIONING_ONE_QUARTER_MAX_SIZE)) {
				FT_Pos xshift = (int)((p_glyph >> 27) & 3) << 4;
				FT_Outline_Translate(&fd->face->glyph->outline, xshift, 0);
			} else if ((p_font_data->subpixel_positioning == SUBPIXEL_POSITIONING_ONE_HALF) || (p_font_data->subpixel_positioning == SUBPIXEL_POSITIONING_AUTO && p_size.x <= SUBPIXEL_POSITIONING_ONE_HALF_MAX_SIZE)) {
				FT_Pos xshift = (int)((p_glyph >> 27) & 3) << 5;
				FT_Outline_Translate(&fd->face->glyph->outline, xshift, 0);
			}
		}
		if (p_font_data->embolden != 0.f) {
			FT_Pos strength = p_font_data->embolden * p_size.x * 4;