### 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)

} else if (!result.is_meta_type) {
					push_error(vformat(R"(Member "%s" under base "%s" is not a valid type.)", p_type->type_chain[i]->name, base.to_string()), p_type->type_chain[1]);
					return bad_type;
				}
			}
		} else if (result.kind == GDScriptParser::DataType::NATIVE) {
			
			if (ClassDB::has_enum(result.native_type, p_type->type_chain[1]->name)) {
				if (p_type->type_chain.size() > 2) {
					push_error(R"(Enums cannot contain nested types.)", p_type->type_chain[2]);
					return bad_type;
				} else {
					result = make_native_enum_type(p_type->type_chain[1]->name, result.native_type);
				}
			} else {
				push_error(vformat(R"(Could not find type "%s" in "%s".)", p_type->type_chain[1]->name, first), p_type->type_chain[1]);
				return bad_type;
			}
		} else {
			push_error(vformat(R"(Could not find nested type "%s" under base "%s".)", p_type->type_chain[1]->name, result.to_string()), p_type->type_chain[1]);
			return bad_type;
		}
	}
	if (result.builtin_type != Variant::ARRAY && p_type->container_type != nullptr) {
		push_error("Only arrays can specify the collection element type.", p_type);
	}
	p_type->set_datatype(result);
	return result;
}
void GDScriptAnalyzer::resolve_class_member(GDScriptParser::ClassNode *p_class, StringName p_name, const GDScriptParser::Node *p_source) {