### 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
register_annotation(MethodInfo("@export_dir"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_DIR, Variant::STRING>);
	register_annotation(MethodInfo("@export_global_file", PropertyInfo(Variant::STRING, "filter")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_GLOBAL_FILE, Variant::STRING>, varray(""), true);
	register_annotation(MethodInfo("@export_global_dir"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_GLOBAL_DIR, Variant::STRING>);
	register_annotation(MethodInfo("@export_multiline"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_MULTILINE_TEXT, Variant::STRING>);
	register_annotation(MethodInfo("@export_placeholder", PropertyInfo(Variant::STRING, "placeholder")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_PLACEHOLDER_TEXT, Variant::STRING>);
	register_annotation(MethodInfo("@export_range", PropertyInfo(Variant::FLOAT, "min"), PropertyInfo(Variant::FLOAT, "max"), PropertyInfo(Variant::FLOAT, "step"), PropertyInfo(Variant::STRING, "extra_hints")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_RANGE, Variant::FLOAT>, varray(1.0, ""), true);
	register_annotation(MethodInfo("@export_exp_easing", PropertyInfo(Variant::STRING, "hints")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_EXP_EASING, Variant::FLOAT>, varray(""), true);
	register_annotation(MethodInfo("@export_color_no_alpha"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_COLOR_NO_ALPHA, Variant::COLOR>);
	register_annotation(MethodInfo("@export_node_path", PropertyInfo(Variant::STRING, "type")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_NODE_PATH_VALID_TYPES, Variant::NODE_PATH>, varray(""), true);
	register_annotation(MethodInfo("@export_flags", PropertyInfo(Variant::STRING, "names")), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_FLAGS, Variant::INT>, varray(), true);
	register_annotation(MethodInfo("@export_flags_2d_render"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_RENDER, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_2d_physics"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_PHYSICS, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_2d_navigation"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_2D_NAVIGATION, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_render"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_RENDER, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_physics"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_PHYSICS, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_3d_navigation"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_3D_NAVIGATION, Variant::INT>);
	register_annotation(MethodInfo("@export_flags_avoidance"), AnnotationInfo::VARIABLE, &GDScriptParser::export_annotations<PROPERTY_HINT_LAYERS_AVOIDANCE, Variant::INT>);
	
	register_annotation(MethodInfo("@export_category", PropertyInfo(Variant::STRING, "name")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_CATEGORY>);
	register_annotation(MethodInfo("@export_group", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_GROUP>, varray(""));
	register_annotation(MethodInfo("@export_subgroup", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_SUBGROUP>, varray(""));
	
	register_annotation(MethodInfo("@warning_ignore", PropertyInfo(Variant::STRING, "warning")), AnnotationInfo::CLASS | AnnotationInfo::VARIABLE | AnnotationInfo::SIGNAL | AnnotationInfo::CONSTANT | AnnotationInfo::FUNCTION | AnnotationInfo::STATEMENT, &GDScriptParser::warning_annotations, varray(), true);
	
	register_annotation(MethodInfo("@rpc", PropertyInfo(Variant::STRING, "mode"), PropertyInfo(Variant::STRING, "sync"), PropertyInfo(Variant::STRING, "transfer_mode"), PropertyInfo(Variant::INT, "transfer_channel")), AnnotationInfo::FUNCTION, &GDScriptParser::rpc_annotation, varray("authority", "call_remote", "unreliable", 0), true);
#ifdef DEBUG_ENABLED
	is_ignoring_warnings = !(bool)GLOBAL_GET("debug/gdscript/warnings/enable");
#endif
}
GDScriptParser::~GDScriptParser() {