### 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
new_annotation.info.default_arguments = p_default_arguments;
	if (p_is_vararg) {
		new_annotation.info.flags |= METHOD_FLAG_VARARG;
	}
	new_annotation.apply = p_apply;
	new_annotation.target_kind = p_target_kinds;
	valid_annotations[p_info.name] = new_annotation;
	return true;
}
GDScriptParser::SuiteNode *GDScriptParser::parse_suite(const String &p_context, SuiteNode *p_suite, bool p_for_lambda) {
	SuiteNode *suite = p_suite != nullptr ? p_suite : alloc_node<SuiteNode>();
	suite->parent_block = current_suite;
	suite->parent_function = current_function;
	current_suite = suite;
	bool multiline = false;
	if (match(GDScriptTokenizer::Token::NEWLINE)) {
		multiline = true;
	}
	if (multiline) {
		if (!consume(GDScriptTokenizer::Token::INDENT, vformat(R"(Expected indented block after %s.)", p_context))) {
			current_suite = suite->parent_block;
			complete_extents(suite);
			return suite;
		}
	}
	reset_extents(suite, current);
	int error_count = 0;
	do {
		if (is_at_end() || (!multiline && previous.type == GDScriptTokenizer::Token::SEMICOLON && check(GDScriptTokenizer::Token::NEWLINE))) {
			break;