### Godot version

v4.0.beta.custom_build [13f0158]

### System information

Windows 10

### Issue description

When doing operations (`begin_complex_operation` and `end_complex_operation`) with multiple selections in TextEdit, some of these selections don't revert upon undo. This behavior is affects some of script editor's operations, like duplicate selection and delete lines.

### Steps to reproduce

Open script editor, make multiple selections. Keep in mind what you have selected. Do duplicate selection (ctrl+shift+D). Undo (ctrl+Z). Compare the result to what you remember.

### Minimal reproduction project

N/A
ERR_FAIL_COND_MSG(carets.size() <= 1, "The main caret should not be removed.");
	ERR_FAIL_INDEX(p_caret, carets.size());
	carets.remove_at(p_caret);
	caret_index_edit_dirty = true;
}
void TextEdit::remove_secondary_carets() {
	carets.resize(1);
	caret_index_edit_dirty = true;
	queue_redraw();
}
void TextEdit::merge_overlapping_carets() {