### Godot version

v4.2.dev4.official [549fcce5f]

### System information

Windows 10

### Issue description

`scene/main/node.cpp:1757 - Parameter "p_node" is null.` when attempting to type after using find function. Does not happen in 4.2dev3.

https://github.com/godotengine/godot/assets/3820082/4a2818f7-cc3b-4b46-a0b1-5bc6a85b4abc


### Steps to reproduce

1) Open any script in the script editor
2) Ctrl+F to select some text that exists in the script
3) Hit escape to re-focus the script editor without placing the caret
4) Attempt to type



### Minimal reproduction project

[find-mrp.zip](https://github.com/godotengine/godot/files/12555561/find-mrp.zip)

Ref<InputEventKey> k = p_event;
	if (k.is_valid()) {
		if (!k->is_pressed()) {
			return;
		}
		
		if (has_focus() && editable && (k->get_unicode() >= 32)) {
			selection_delete();
			char32_t ucodestr[2] = { (char32_t)k->get_unicode(), 0 };
			int prev_len = text.length();
			insert_text_at_caret(ucodestr);
			if (text.length() != prev_len) {
				_text_changed();
			}
			accept_event();
		}
	}
}
void LineEdit::gui_input(const Ref<InputEvent> &p_event) {