### 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 (p_variable->property == VariableNode::PROP_INLINE) {
				push_line(":");
				increase_indent();
				print_suite(p_variable->getter->body);
				decrease_indent();
			} else {
				push_line(" =");
				increase_indent();
				print_identifier(p_variable->getter_pointer);
				push_line();
				decrease_indent();
			}
		}
		if (p_variable->setter != nullptr) {
			push_text("Set (");
			if (p_variable->property == VariableNode::PROP_INLINE) {
				if (p_variable->setter_parameter != nullptr) {
					print_identifier(p_variable->setter_parameter);
				} else {
					push_text("<missing>");
				}
				push_line("):");
				increase_indent();
				print_suite(p_variable->setter->body);
				decrease_indent();
			} else {
				push_line(" =");
				increase_indent();
				print_identifier(p_variable->setter_pointer);
				push_line();