### 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
if (class_name != StringName() && native_base != StringName() && ClassDB::is_parent_class(native_base, SNAME("Resource"))) {
					variable->export_info.type = Variant::OBJECT;
					variable->export_info.hint = PROPERTY_HINT_RESOURCE_TYPE;
					variable->export_info.hint_string = class_name;
				}
			} break;
			case GDScriptParser::DataType::ENUM: {
				variable->export_info.type = Variant::INT;
				variable->export_info.hint = PROPERTY_HINT_ENUM;
				String enum_hint_string;
				bool first = true;
				for (const KeyValue<StringName, int64_t> &E : export_type.enum_values) {
					if (!first) {
						enum_hint_string += ",";
					} else {
						first = false;
					}
					enum_hint_string += E.key.operator String().capitalize().xml_escape();
					enum_hint_string += ":";
					enum_hint_string += String::num_int64(E.value).xml_escape();
				}
				variable->export_info.hint_string = enum_hint_string;
			} break;
			default:
				push_error(R"(Export type can only be built-in, a resource, a node, or an enum.)", variable);
				break;
		}
		if (is_array) {
			String hint_prefix = itos(variable->export_info.type);
			if (variable->export_info.hint) {