### 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)
}
						}
					}
					if (sd_glyphs[i].flags & GRAPHEME_IS_RTL) {
						gl.flags |= GRAPHEME_IS_RTL;
						for (int j = sd_glyphs[i].count - 1; j >= 0; j--) {
							sd_glyphs_new[sd_shift + i + j + 1] = sd_glyphs_new[sd_shift + i + j];
						}
						sd_glyphs_new[sd_shift + i] = gl;
					} else {
						sd_glyphs_new[sd_shift + i + count] = gl;
					}
					sd_shift++;
					ERR_FAIL_COND_V_MSG(sd_shift > sd->break_inserts, false, "Invalid break insert count!");
				}
			}
			i += (sd_glyphs[i].count - 1);
		}
	}
	if (sd_shift < sd->break_inserts) {
		
		glyphs_new.resize(sd->glyphs.size() + sd_shift);
	}
	if (sd->break_inserts > 0) {
		sd->glyphs = glyphs_new;
	}
	sd->line_breaks_valid = true;
	return sd->line_breaks_valid;
}