### 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)
}
							Glyph gl;
							gl.start = span.start;
							gl.end = span.end;
							gl.count = 1;
							gl.flags = GRAPHEME_IS_VALID | GRAPHEME_IS_EMBEDDED_OBJECT;
							if (sd->orientation == ORIENTATION_HORIZONTAL) {
								gl.advance = sd->objects[span.embedded_key].rect.size.x;
							} else {
								gl.advance = sd->objects[span.embedded_key].rect.size.y;
							}
							sd->glyphs.push_back(gl);
						} else {
							Array fonts;
							Array fonts_scr_only;
							Array fonts_no_match;
							int font_count = span.fonts.size();
							if (font_count > 0) {
								fonts.push_back(sd->spans[k].fonts[0]);
							}
							for (int l = 1; l < font_count; l++) {
								if (_font_is_script_supported(span.fonts[l], script_code)) {
									if (_font_is_language_supported(span.fonts[l], span.language)) {
										fonts.push_back(sd->spans[k].fonts[l]);
									} else {
										fonts_scr_only.push_back(sd->spans[k].fonts[l]);
									}
								} else {
									fonts_no_match.push_back(sd->spans[k].fonts[l]);
								}