### 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_await->to_await == nullptr) {
		GDScriptParser::DataType await_type;
		await_type.kind = GDScriptParser::DataType::VARIANT;
		p_await->set_datatype(await_type);
		return;
	}
	if (p_await->to_await->type == GDScriptParser::Node::CALL) {
		reduce_call(static_cast<GDScriptParser::CallNode *>(p_await->to_await), true);
	} else {
		reduce_expression(p_await->to_await);
	}
	GDScriptParser::DataType await_type = p_await->to_await->get_datatype();
	
	if (await_type.is_hard_type() && await_type.kind == GDScriptParser::DataType::BUILTIN && await_type.builtin_type == Variant::SIGNAL) {
		await_type.kind = GDScriptParser::DataType::VARIANT;
		await_type.type_source = GDScriptParser::DataType::UNDETECTED;
	} else if (p_await->to_await->is_constant) {
		p_await->is_constant = p_await->to_await->is_constant;
		p_await->reduced_value = p_await->to_await->reduced_value;
	}
	await_type.is_coroutine = false;
	p_await->set_datatype(await_type);
#ifdef DEBUG_ENABLED
	GDScriptParser::DataType to_await_type = p_await->to_await->get_datatype();
	if (!to_await_type.is_coroutine && !to_await_type.is_variant() && to_await_type.builtin_type != Variant::SIGNAL) {
		parser->push_warning(p_await, GDScriptWarning::REDUNDANT_AWAIT);
	}
#endif
}
void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_op) {