### 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)

ERR_FAIL_COND_MSG(!parser->valid_annotations.has(p_annotation->name), vformat(R"(Annotation "%s" not found to validate.)", p_annotation->name));
	if (p_annotation->is_resolved) {
		return;
	}
	p_annotation->is_resolved = true;
	const MethodInfo &annotation_info = parser->valid_annotations[p_annotation->name].info;
	const List<PropertyInfo>::Element *E = annotation_info.arguments.front();
	for (int i = 0; i < p_annotation->arguments.size(); i++) {
		GDScriptParser::ExpressionNode *argument = p_annotation->arguments[i];
		const PropertyInfo &argument_info = E->get();
		if (E->next() != nullptr) {
			E = E->next();
		}
		reduce_expression(argument);