### 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 (const KeyValue<StringName, IdentifierNode *> &E : branch->patterns[0]->binds) {
			SuiteNode::Local local(E.value, current_function);
			local.type = SuiteNode::Local::PATTERN_BIND;
			suite->add_local(local);
		}
	}
	branch->block = parse_suite("match pattern block", suite);
	complete_extents(branch);
	return branch;
}
GDScriptParser::PatternNode *GDScriptParser::parse_match_pattern(PatternNode *p_root_pattern) {
	PatternNode *pattern = alloc_node<PatternNode>();
	reset_extents(pattern, current);
	switch (current.type) {
		case GDScriptTokenizer::Token::VAR: {
			
			advance();
			if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected bind name after "var".)")) {
				complete_extents(pattern);
				return nullptr;
			}
			pattern->pattern_type = PatternNode::PT_BIND;
			pattern->bind = parse_identifier();
			PatternNode *root_pattern = p_root_pattern == nullptr ? pattern : p_root_pattern;
			if (p_root_pattern != nullptr) {
				if (p_root_pattern->has_bind(pattern->bind->name)) {
					push_error(vformat(R"(Bind variable name "%s" was already used in this pattern.)", pattern->bind->name));
					complete_extents(pattern);
					return nullptr;
				}