### Godot version

4.0 beta 10

### System information

Windows 10

### Issue description

Godot crashes when i accidently name 2 items in an enum the same

EDIT:
The editor freeze for some seconds, then both editor- and console-window dissapear

### Steps to reproduce

Write

```gdscript
enum {
    A,
}
```

and then add a second line with another A:

```gdscript
enum {
    A,
    A # <- crash
}
```

Does not always immediatly happen if i copy&paste items.
Does not happen when i change the script in another editor and open the script in Godot.

### Minimal reproduction project

[enum.zip](https://github.com/godotengine/godot/files/10313759/enum.zip)

mark_node_unsafe(p_assignment);
				if (assignee_is_hard) {
					if (is_type_compatible(op_type, assignee_type, true, p_assignment->assigned_value)) {
						
						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;
				}
			}
		}
	}
	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) {