Enum does not update in resource on change it needs restart to update

### Tested versions

Reproducible in:
4.4Dev-3
4.4Dev-4
4.4Dev-5
4.4Dev-6

### System information

Linux Manjaro, Nvidia Geforce GTX 850, CPU: intel i7

### Issue description

when in resource you place a enum as typed variable you may choose the enums that are written like:

```gdscript
enum example{
one,
two,
three,
}
```

all works well
but if you add "four" you won't see it in the resources
you need to restart the godot and wala there it is

so each time you add an enums or change names you need to restart the godot to take effect

### Steps to reproduce

1. create node with variable (array) that contains resources
2. create resource and attach it
3. add enum variable in resource
4. add enum variable
5. and try to set it in node at first step -> it's array (any one) -> it's enum variable

it's not there

6. restart godot

it's there.

### Minimal reproduction project (MRP)

N/A