### Godot version

v4.0.rc1.official [8843d9ad3]

### System information

Lubuntu

### Issue description

You can't use + or += to mutate typed arrays.

It seems to be not correctly getting the type information from the second operand.

An erudite poster on the discord puts it differently:
> it's more like operator + doesn't retain Array typing
> the syntax for Array Concatenation via operators, but the idea gets across i think


The error you see is:
```Trying to assign an array of type "Array" to a variable of type "Array[int]".```


### Steps to reproduce

```
	var Alice: Array[int] = [1,2,3]
	var Bob: Array[int] = [4,5,6]
	Alice += Bob
```
This will crash with the above error message.

### Minimal reproduction project

[plus_syntax_broken_demo_project.zip](https://github.com/godotengine/godot/files/10694514/plus_syntax_broken_demo_project.zip)

if (base_class->fqcn == p_class->fqcn) {
			push_error("Cyclic inheritance.", p_class);
			return ERR_PARSE_ERROR;
		}
		base_class = base_class->base_type.class_type;
	}
	p_class->base_type = result;
	class_type.native_type = result.native_type;
	p_class->set_datatype(class_type);
	parser->current_class = previous_class;
	return OK;
}
Error GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode *p_class, bool p_recursive) {
	Error err = resolve_class_inheritance(p_class);
	if (err) {
		return err;
	}
	if (p_recursive) {
		for (int i = 0; i < p_class->members.size(); i++) {
			if (p_class->members[i].type == GDScriptParser::ClassNode::Member::CLASS) {
				err = resolve_class_inheritance(p_class->members[i].m_class, true);
				if (err) {
					return err;
				}
			}
		}
	}
	return OK;
}
GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(GDScriptParser::TypeNode *p_type) {