### 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)
case INLINE_ALIGNMENT_TO_BASELINE: {
						E.value.rect.position.x = 0;
					} 
					case INLINE_ALIGNMENT_TO_BOTTOM: {
						E.value.rect.position.x = p_sd->descent;
					} 
				}
				switch (E.value.inline_align & INLINE_ALIGNMENT_IMAGE_MASK) {
					case INLINE_ALIGNMENT_BOTTOM_TO: {
						E.value.rect.position.x -= E.value.rect.size.x;
					} 
					case INLINE_ALIGNMENT_CENTER_TO: {
						E.value.rect.position.x -= E.value.rect.size.x / 2;
					} 
					case INLINE_ALIGNMENT_BASELINE_TO: {
						E.value.rect.position.x -= E.value.baseline;
					} 
					case INLINE_ALIGNMENT_TOP_TO: {
						
					} 
				}
				full_ascent = MAX(full_ascent, -E.value.rect.position.x);
				full_descent = MAX(full_descent, E.value.rect.position.x + E.value.rect.size.x);
			}
		}
	}
	p_sd->ascent = full_ascent;
	p_sd->descent = full_descent;
}
RID TextServerAdvanced::_shaped_text_substr(const RID &p_shaped, int64_t p_start, int64_t p_length) const {