### 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 = sd_glyphs[i].start;
						gl.end = sd_glyphs[i].end;
						gl.count = 1;
						gl.font_rid = sd_glyphs[i].font_rid;
						gl.font_size = sd_glyphs[i].font_size;
						gl.flags = GRAPHEME_IS_SPACE | GRAPHEME_IS_VIRTUAL;
						if (sd_glyphs[i].flags & GRAPHEME_IS_RTL) {
							gl.flags |= GRAPHEME_IS_RTL;
							sd->glyphs.insert(i, gl); 
						} else {
							sd->glyphs.insert(i + count, gl); 
						}
						i += count;
						
						sd_size = sd->glyphs.size();
						sd_glyphs = sd->glyphs.ptrw();
						continue;
					}
				}
			}
		}
	}
	sd->justification_ops_valid = true;
	return sd->justification_ops_valid;
}
Glyph TextServerAdvanced::_shape_single_glyph(ShapedTextDataAdvanced *p_sd, char32_t p_char, hb_script_t p_script, hb_direction_t p_direction, const RID &p_font, int64_t p_font_size) {