### 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)

p_identifier->is_constant = true;
					p_identifier->reduced_value = member.constant->initializer->reduced_value;
					p_identifier->source = GDScriptParser::IdentifierNode::MEMBER_CONSTANT;
					p_identifier->constant_source = member.constant;
					return;
				}
				case GDScriptParser::ClassNode::Member::ENUM_VALUE: {
					p_identifier->set_datatype(member.get_datatype());
					p_identifier->is_constant = true;
					p_identifier->reduced_value = member.enum_value.value;
					p_identifier->source = GDScriptParser::IdentifierNode::MEMBER_CONSTANT;
					return;
				}
				case GDScriptParser::ClassNode::Member::ENUM: {
					p_identifier->set_datatype(member.get_datatype());
					p_identifier->is_constant = true;
					p_identifier->reduced_value = member.m_enum->dictionary;
					p_identifier->source = GDScriptParser::IdentifierNode::MEMBER_CONSTANT;
					return;
				}
				case GDScriptParser::ClassNode::Member::VARIABLE: {
					if (is_base && !base.is_meta_type) {
						p_identifier->set_datatype(member.get_datatype());
						p_identifier->source = GDScriptParser::IdentifierNode::MEMBER_VARIABLE;
						p_identifier->variable_source = member.variable;
						member.variable->usages += 1;
						return;
					}
				} break;
				case GDScriptParser::ClassNode::Member::SIGNAL: {