### Godot version

v4.0.beta13.official [caacade56]

### System information

Windows 8.1

### Issue description

The `Unreachable code (statement after return) in function 'function_name()'` warning is given for functions that do not have unreachable code. The same code does not give this warning in v3.5.stable.official [991bb6ac7].

### Steps to reproduce

```
func warning(i: int) -> void:
  if i == 0:
    pass
  elif i == 1:
    return
  else:
    return
  print("yeah")
```

Removing either the `elif` or the `else` removes the warning.

### Minimal reproduction project

N/A; code in reproduction steps can be placed in any blank gdscript file to trigger the error.
if (!for_completion) {
		return;
	}
	CompletionCall call;
	call.call = p_call;
	call.argument = 0;
	completion_call_stack.push_back(call);
	if (previous.cursor_place == GDScriptTokenizer::CURSOR_MIDDLE || previous.cursor_place == GDScriptTokenizer::CURSOR_END || current.cursor_place == GDScriptTokenizer::CURSOR_BEGINNING) {
		completion_call = call;
	}
}
void GDScriptParser::pop_completion_call() {
	if (!for_completion) {
		return;
	}
	ERR_FAIL_COND_MSG(completion_call_stack.is_empty(), "Trying to pop empty completion call stack");
	completion_call_stack.pop_back();
}
void GDScriptParser::set_last_completion_call_arg(int p_argument) {
	if (!for_completion || passed_cursor) {
		return;
	}
	ERR_FAIL_COND_MSG(completion_call_stack.is_empty(), "Trying to set argument on empty completion call stack");
	completion_call_stack.back()->get().argument = p_argument;
}
Error GDScriptParser::parse(const String &p_source_code, const String &p_script_path, bool p_for_completion) {