### 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
for (int i = 0; i < p_match_branch->patterns.size(); i++) {
		if (i > 0) {
			push_text(" , ");
		}
		print_match_pattern(p_match_branch->patterns[i]);
	}
	push_line(" :");
	increase_indent();
	print_suite(p_match_branch->block);
	decrease_indent();
}
void GDScriptParser::TreePrinter::print_match_pattern(PatternNode *p_match_pattern) {
	switch (p_match_pattern->pattern_type) {
		case PatternNode::PT_LITERAL:
			print_literal(p_match_pattern->literal);
			break;
		case PatternNode::PT_WILDCARD:
			push_text("_");
			break;
		case PatternNode::PT_REST:
			push_text("..");
			break;
		case PatternNode::PT_BIND:
			push_text("Var ");
			print_identifier(p_match_pattern->bind);
			break;
		case PatternNode::PT_EXPRESSION: