### 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
}
			item.index = enum_node->values.size();
			enum_node->values.push_back(item);
			if (!named) {
				
				current_class->add_member(item);
			}
		}
	} while (match(GDScriptTokenizer::Token::COMMA));
	pop_multiline();
	consume(GDScriptTokenizer::Token::BRACE_CLOSE, R"(Expected closing "}" for enum.)");
#ifdef TOOLS_ENABLED
	
	for (int i = 0; i < enum_node->values.size(); i++) {
		if (i == enum_node->values.size() - 1) {
			
			if (enum_node->values[i].line != previous.start_line && has_comment(enum_node->values[i].line)) {
				if (named) {
					enum_node->values.write[i].doc_description = get_doc_comment(enum_node->values[i].line, true);
				} else {
					current_class->set_enum_value_doc(enum_node->values[i].identifier->name, get_doc_comment(enum_node->values[i].line, true));
				}
			}
		} else {
			
			if (enum_node->values[i].line != enum_node->values[i + 1].line && has_comment(enum_node->values[i].line)) {
				if (named) {
					enum_node->values.write[i].doc_description = get_doc_comment(enum_node->values[i].line, true);
				} else {
					current_class->set_enum_value_doc(enum_node->values[i].identifier->name, get_doc_comment(enum_node->values[i].line, true));