### 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)

result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
		result.kind = GDScriptParser::DataType::BUILTIN;
		result.builtin_type = Variant::BOOL;
	} else if (left_type.is_variant() || right_type.is_variant()) {
		
		result.kind = GDScriptParser::DataType::VARIANT;
		mark_node_unsafe(p_binary_op);
	} else if (p_binary_op->variant_op < Variant::OP_MAX) {
		bool valid = false;
		result = get_operation_type(p_binary_op->variant_op, left_type, right_type, valid, p_binary_op);
		if (!valid) {
			push_error(vformat(R"(Invalid operands "%s" and "%s" for "%s" operator.)", left_type.to_string(), right_type.to_string(), Variant::get_operator_name(p_binary_op->variant_op)), p_binary_op);
		} else if (!result.is_hard_type()) {
			mark_node_unsafe(p_binary_op);
		}
	} else {
		ERR_PRINT("Parser bug: unknown binary operation.");
	}
	p_binary_op->set_datatype(result);
}
#ifdef SUGGEST_GODOT4_RENAMES
const char *get_rename_from_map(const char *map[][2], String key) {
	for (int index = 0; map[index][0]; index++) {
		if (map[index][0] == key) {
			return map[index][1];
		}
	}
	return nullptr;
}
const char *check_for_renamed_identifier(String identifier, GDScriptParser::Node::Type type) {