### 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)

resolve_function_body(p_lambda->function, true);
	lambda_stack.pop_back();
	int captures_amount = p_lambda->captures.size();
	if (captures_amount > 0) {
		
		
		int param_count = p_lambda->function->parameters.size();
		p_lambda->function->parameters.resize(param_count + captures_amount);
		for (int i = param_count - 1; i >= 0; i--) {
			p_lambda->function->parameters.write[i + captures_amount] = p_lambda->function->parameters[i];
			p_lambda->function->parameters_indices[p_lambda->function->parameters[i]->identifier->name] = i + captures_amount;
		}
		
		for (int i = 0; i < p_lambda->captures.size(); i++) {
			GDScriptParser::IdentifierNode *capture = p_lambda->captures[i];
			GDScriptParser::ParameterNode *capture_param = parser->alloc_node<GDScriptParser::ParameterNode>();
			capture_param->identifier = capture;
			capture_param->usages = capture->usages;
			capture_param->set_datatype(capture->get_datatype());
			p_lambda->function->parameters.write[i] = capture_param;
			p_lambda->function->parameters_indices[capture->name] = i;
		}
	}
}
void GDScriptAnalyzer::reduce_literal(GDScriptParser::LiteralNode *p_literal) {
	p_literal->reduced_value = p_literal->value;
	p_literal->is_constant = true;
	p_literal->set_datatype(type_from_variant(p_literal->reduced_value, p_literal));
}
void GDScriptAnalyzer::reduce_preload(GDScriptParser::PreloadNode *p_preload) {