### 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)
}
			int32_t bidi_run_start = _convert_pos(sd, start + _bidi_run_start);
			int32_t bidi_run_end = _convert_pos(sd, start + _bidi_run_start + _bidi_run_length);
			
			int scr_from = (is_rtl) ? 0 : sd->script_iter->script_ranges.size() - 1;
			int scr_to = (is_rtl) ? sd->script_iter->script_ranges.size() : -1;
			int scr_delta = (is_rtl) ? +1 : -1;
			for (int j = scr_from; j != scr_to; j += scr_delta) {
				if ((sd->script_iter->script_ranges[j].start < bidi_run_end) && (sd->script_iter->script_ranges[j].end > bidi_run_start)) {
					int32_t script_run_start = MAX(sd->script_iter->script_ranges[j].start, bidi_run_start);
					int32_t script_run_end = MIN(sd->script_iter->script_ranges[j].end, bidi_run_end);
					char scr_buffer[5] = { 0, 0, 0, 0, 0 };
					hb_tag_to_string(hb_script_to_iso15924_tag(sd->script_iter->script_ranges[j].script), scr_buffer);
					String script_code = String(scr_buffer);
					int spn_from = (is_rtl) ? 0 : sd->spans.size() - 1;
					int spn_to = (is_rtl) ? sd->spans.size() : -1;
					int spn_delta = (is_rtl) ? +1 : -1;
					for (int k = spn_from; k != spn_to; k += spn_delta) {
						const ShapedTextDataAdvanced::Span &span = sd->spans[k];
						if (span.start - sd->start >= script_run_end || span.end - sd->start <= script_run_start) {
							continue;
						}
						if (span.embedded_key != Variant()) {
							
							if (sd->orientation == ORIENTATION_HORIZONTAL) {
								sd->objects[span.embedded_key].rect.position.x = sd->width;
								sd->width += sd->objects[span.embedded_key].rect.size.x;
							} else {
								sd->objects[span.embedded_key].rect.position.y = sd->width;
								sd->width += sd->objects[span.embedded_key].rect.size.y;