### 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
return check(GDScriptTokenizer::Token::NEWLINE) || check(GDScriptTokenizer::Token::SEMICOLON) || check(GDScriptTokenizer::Token::TK_EOF);
}
bool GDScriptParser::is_statement_end() const {
	return lambda_ended || in_lambda || is_statement_end_token();
}
void GDScriptParser::end_statement(const String &p_context) {
	bool found = false;
	while (is_statement_end() && !is_at_end()) {
		
		if (is_statement_end_token()) {
			
			advance();
		} else if (lambda_ended) {
			lambda_ended = false; 
			found = true;
			break;
		} else {
			if (!found) {
				lambda_ended = true; 
				found = true;
			}
			break;
		}
		found = true;
	}
	if (!found && !is_at_end()) {
		push_error(vformat(R"(Expected end of statement after %s, found "%s" instead.)", p_context, current.get_name()));
	}
}
void GDScriptParser::parse_program() {