### 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)

const GDScriptParser::DataType *current_data_type = &p_class_node->base_type;
	while (current_data_type && current_data_type->kind == GDScriptParser::DataType::Kind::CLASS) {
		GDScriptParser::ClassNode *current_class_node = current_data_type->class_type;
		if (has_member_name_conflict_in_script_class(p_member_name, current_class_node, p_member_node)) {
			String parent_class_name = current_class_node->fqcn;
			if (current_class_node->identifier != nullptr) {
				parent_class_name = current_class_node->identifier->name;
			}
			push_error(vformat(R"(The member "%s" already exists in parent class %s.)", p_member_name, parent_class_name), p_member_node);
			return ERR_PARSE_ERROR;
		}
		current_data_type = &current_class_node->base_type;
	}
	
	if (current_data_type && current_data_type->kind == GDScriptParser::DataType::Kind::NATIVE) {
		if (current_data_type->native_type != StringName()) {
			return check_native_member_name_conflict(
					p_member_name,
					p_member_node,
					current_data_type->native_type);
		}
	}
	return OK;
}
void GDScriptAnalyzer::get_class_node_current_scope_classes(GDScriptParser::ClassNode *p_node, List<GDScriptParser::ClassNode *> *p_list) {