### 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 (setter_function == nullptr) {
						push_error(vformat(R"(Setter "%s" not found.)", member.variable->setter_pointer->name), member.variable);
					} else if (setter_function->parameters.size() != 1) {
						push_error(vformat(R"(Function "%s" cannot be used as setter because of its signature.)", setter_function->identifier->name), member.variable);
					} else if (!is_type_compatible(member.variable->datatype, setter_function->parameters[0]->datatype, true)) {
						push_error(vformat(R"(Function with argument type "%s" cannot be used as setter for a property of type "%s".)", setter_function->parameters[0]->datatype.to_string(), member.variable->datatype.to_string()), member.variable);
					} else {
						has_valid_setter = true;
#ifdef DEBUG_ENABLED
						if (member.variable->datatype.builtin_type == Variant::FLOAT && setter_function->parameters[0]->datatype.builtin_type == Variant::INT) {
							parser->push_warning(member.variable, GDScriptWarning::NARROWING_CONVERSION);
						}
#endif
					}
				}
				if (member.variable->datatype.is_variant() && has_valid_getter && has_valid_setter) {
					if (!is_type_compatible(getter_function->datatype, setter_function->parameters[0]->datatype, true)) {
						push_error(vformat(R"(Getter with type "%s" cannot be used along with setter of type "%s".)", getter_function->datatype.to_string(), setter_function->parameters[0]->datatype.to_string()), member.variable);
					}
				}
			}
#ifdef DEBUG_ENABLED
			parser->ignored_warnings = previously_ignored_warnings;
#endif 
		}
	}
	parser->current_class = previous_class;
}
void GDScriptAnalyzer::resolve_class_body(GDScriptParser::ClassNode *p_class, bool p_recursive) {