### 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
CHECK(text_edit->get_selection_from_line(1) == 2);
			CHECK(text_edit->get_selection_from_column(1) == 0);
			CHECK(text_edit->get_selection_to_line(1) == 2);
			CHECK(text_edit->get_selection_to_column(1) == 4);
			CHECK(text_edit->get_caret_line(1) == 2);
			CHECK(text_edit->get_caret_column(1) == 4);
			CHECK(text_edit->get_caret_count() == 2);
			text_edit->select_word_under_caret();
			CHECK_FALSE(text_edit->has_selection());
			CHECK(text_edit->get_selected_text() == "");
			SEND_GUI_ACTION("ui_text_select_word_under_caret");
			CHECK(text_edit->get_viewport()->is_input_handled());
			MessageQueue::get_singleton()->flush();
			CHECK(text_edit->has_selection(0));
			CHECK(text_edit->get_selected_text(0) == "test");
			CHECK(text_edit->get_selection_from_line(0) == 1);
			CHECK(text_edit->get_selection_from_column(0) == 0);
			CHECK(text_edit->get_selection_to_line(0) == 1);
			CHECK(text_edit->get_selection_to_column(0) == 4);
			CHECK(text_edit->get_caret_line(0) == 1);
			CHECK(text_edit->get_caret_column(0) == 4);
			CHECK(text_edit->has_selection(1));
			CHECK(text_edit->get_selected_text(1) == "test");
			CHECK(text_edit->get_selection_from_line(1) == 2);
			CHECK(text_edit->get_selection_from_column(1) == 0);
			CHECK(text_edit->get_selection_to_line(1) == 2);
			CHECK(text_edit->get_selection_to_column(1) == 4);
			CHECK(text_edit->get_caret_line(1) == 2);
			CHECK(text_edit->get_caret_column(1) == 4);
			CHECK(text_edit->get_selected_text() == "test\ntest");