### 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)

for (int i = 0; i < p_array->elements.size(); i++) {
		GDScriptParser::ExpressionNode *element_node = p_array->elements[i];
		if (element_node->is_constant) {
			update_const_expression_builtin_type(element_node, p_element_type, "include");
		}
		const GDScriptParser::DataType &element_type = element_node->get_datatype();
		if (element_type.has_no_type() || element_type.is_variant() || !element_type.is_hard_type()) {
			mark_node_unsafe(element_node);
			continue;
		}
		if (!is_type_compatible(p_element_type, element_type, true, p_array)) {
			if (is_type_compatible(element_type, p_element_type)) {
				mark_node_unsafe(element_node);
				continue;
			}
			push_error(vformat(R"(Cannot have an element of type "%s" in an array of type "Array[%s]".)", element_type.to_string(), p_element_type.to_string()), element_node);
			return;
		}
	}
	GDScriptParser::DataType array_type = p_array->get_datatype();
	array_type.set_container_element_type(p_element_type);
	p_array->set_datatype(array_type);
}
void GDScriptAnalyzer::reduce_assignment(GDScriptParser::AssignmentNode *p_assignment) {