### 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)
for (int j = r_start; j < r_end; j++) {
					char32_t c = sd->text[j - sd->start];
					if (is_whitespace(c)) {
						sd->breaks[j + 1] = false;
					}
					if (is_linebreak(c)) {
						sd->breaks[j + 1] = true;
					}
				}
			} else {
				while (ubrk_next(bi) != UBRK_DONE) {
					int pos = _convert_pos(sd, ubrk_current(bi)) + r_start;
					if ((ubrk_getRuleStatus(bi) >= UBRK_LINE_HARD) && (ubrk_getRuleStatus(bi) < UBRK_LINE_HARD_LIMIT)) {
						sd->breaks[pos] = true;
					} else if ((ubrk_getRuleStatus(bi) >= UBRK_LINE_SOFT) && (ubrk_getRuleStatus(bi) < UBRK_LINE_SOFT_LIMIT)) {
						sd->breaks[pos] = false;
					}
					int pos_p = pos - 1 - sd->start;
					char32_t c = sd->text[pos_p];
					if (pos - sd->start != sd->end && !is_whitespace(c) && (c != 0xfffc)) {
						sd->break_inserts++;
					}
				}
			}
			ubrk_close(bi);
			i++;
		}
		sd->break_ops_valid = true;
	}
	Vector<Glyph> glyphs_new;