### 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 (is_type_compatible(op_type, assignee_type)) {
						
						p_assignment->use_conversion_assign = true;
					} else {
						
						push_error(vformat(R"(Value of type "%s" cannot be assigned to a variable of type "%s".)", assigned_value_type.to_string(), assignee_type.to_string()), p_assignment->assigned_value);
					}
				} else {
					
					downgrades_assignee = true;
				}
			} else if (assignee_type.has_container_element_type() && !op_type.has_container_element_type()) {
				
				mark_node_unsafe(p_assignment);
			}
		}
	}
	if (downgrades_assignee) {
		downgrade_node_type_source(p_assignment->assignee);
	}
	if (downgrades_assigned) {
		downgrade_node_type_source(p_assignment->assigned_value);
	}
#ifdef DEBUG_ENABLED
	if (assignee_type.is_hard_type() && assignee_type.builtin_type == Variant::INT && assigned_value_type.builtin_type == Variant::FLOAT) {
		parser->push_warning(p_assignment->assigned_value, GDScriptWarning::NARROWING_CONVERSION);
	}
#endif
}
void GDScriptAnalyzer::reduce_await(GDScriptParser::AwaitNode *p_await) {