### 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)

if (p_binary_op->variant_op == Variant::OP_DIVIDE && left_type.builtin_type == Variant::INT && right_type.builtin_type == Variant::INT) {
		parser->push_warning(p_binary_op, GDScriptWarning::INTEGER_DIVISION);
	}
#endif
	if (p_binary_op->left_operand->is_constant && p_binary_op->right_operand->is_constant) {
		p_binary_op->is_constant = true;
		if (p_binary_op->variant_op < Variant::OP_MAX) {
			bool valid = false;
			Variant::evaluate(p_binary_op->variant_op, p_binary_op->left_operand->reduced_value, p_binary_op->right_operand->reduced_value, p_binary_op->reduced_value, valid);
			if (!valid) {
				if (p_binary_op->reduced_value.get_type() == Variant::STRING) {
					push_error(vformat(R"(%s in operator %s.)", p_binary_op->reduced_value, Variant::get_operator_name(p_binary_op->variant_op)), p_binary_op);
				} else {
					push_error(vformat(R"(Invalid operands to operator %s, %s and %s.)",
									   Variant::get_operator_name(p_binary_op->variant_op),
									   Variant::get_type_name(p_binary_op->left_operand->reduced_value.get_type()),
									   Variant::get_type_name(p_binary_op->right_operand->reduced_value.get_type())),
							p_binary_op);
				}
			}
		} else {
			ERR_PRINT("Parser bug: unknown binary operation.");
		}
		p_binary_op->set_datatype(type_from_variant(p_binary_op->reduced_value, p_binary_op));
		return;
	}
	GDScriptParser::DataType result;
	if ((p_binary_op->variant_op == Variant::OP_EQUAL || p_binary_op->variant_op == Variant::OP_NOT_EQUAL) &&
			((left_type.kind == GDScriptParser::DataType::BUILTIN && left_type.builtin_type == Variant::NIL) || (right_type.kind == GDScriptParser::DataType::BUILTIN && right_type.builtin_type == Variant::NIL))) {