Deleting Unfound Nodes

### Expected Behavior

Expected behavior is to be able to remove old custom nodes from the workspace of workflows that previously included the deleted node.

### Actual Behavior

I've built workflows with nodes that I ended up removing from the custom node pack. when using a workflow with the old node, I'm unable to delete the old node from the interface.

### Steps to Reproduce

Just try deleting the .py for a custom node, and then open a workflow that had it already in the workspace, then try to delete that node.

### Debug Logs

```powershell
Whether selecting and hitting delete, or clicking the delete trash icon over the node when selected, the node remains on the workspace and an error pops up saying: Cannot read properties of null (reading '1').

Nothing appears in the logs in relation to this.

```

### Other

_No response_