### Godot version

4.0 stable

### System information

Fedora, RX 590

### Issue description

I made a dictionary, and instead of using `:` to separate between key and value, i accidentally used `=`.
The error message was not clear at all `Parse Error: Expected identifier or string as LUA-style dictionary key.` 

I don't think assuming that people know how dictionaries are made in LUA is reasonable. And if this is not about LUA the programming language, i don't even know what this is about :D

I think this error should be replaced with something of the sort "Please use `:` as separator instead of `=` in your dictionary"

### Steps to reproduce

Paste this code in a script:

```

var dict = {
	1 = "lala"
}
```

Observe the error message
![image](https://user-images.githubusercontent.com/7917475/224549538-38ea25aa-ba75-431e-868b-0733a53b90ad.png)


### Minimal reproduction project

see above
clear();
}
void GDScriptParser::clear() {
	while (list != nullptr) {
		Node *element = list;
		list = list->next;
		memdelete(element);
	}
	head = nullptr;
	list = nullptr;
	_is_tool = false;
	for_completion = false;
	errors.clear();
	multiline_stack.clear();
	nodes_in_progress.clear();
}
void GDScriptParser::push_error(const String &p_message, const Node *p_origin) {
	
	
	panic_mode = true;
	
	if (p_origin == nullptr) {
		errors.push_back({ p_message, current.start_line, current.start_column });
	} else {
		errors.push_back({ p_message, p_origin->start_line, p_origin->leftmost_column });
	}
}
#ifdef DEBUG_ENABLED
void GDScriptParser::push_warning(const Node *p_source, GDScriptWarning::Code p_code, const Vector<String> &p_symbols) {