### 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
case Node::LAMBDA:
			print_lambda(static_cast<LambdaNode *>(p_expression));
			break;
		case Node::LITERAL:
			print_literal(static_cast<LiteralNode *>(p_expression));
			break;
		case Node::PRELOAD:
			print_preload(static_cast<PreloadNode *>(p_expression));
			break;
		case Node::SELF:
			print_self(static_cast<SelfNode *>(p_expression));
			break;
		case Node::SUBSCRIPT:
			print_subscript(static_cast<SubscriptNode *>(p_expression));
			break;
		case Node::TERNARY_OPERATOR:
			print_ternary_op(static_cast<TernaryOpNode *>(p_expression));
			break;
		case Node::TYPE_TEST:
			print_type_test(static_cast<TypeTestNode *>(p_expression));
			break;
		case Node::UNARY_OPERATOR:
			print_unary_op(static_cast<UnaryOpNode *>(p_expression));
			break;
		default:
			push_text(vformat("<unknown expression %d>", p_expression->type));
			break;
	}
}
void GDScriptParser::TreePrinter::print_enum(EnumNode *p_enum) {