[NODES] Deleting node group keeps connection intact

[mcDandy]

Commit Hash 3bc53cef

Platform Windows 11

Summary When you create group and than delete the group the connection will presist

1. create a sequence with a clip or solid
2. add a node (does not matter what) somewhere in the clip so it disapearance affects output
3. group that node
4. delete ONLY the group without disconnecting
5. no difference

Additional Information / Output I somehow managed to crash olive by double deleting group, but I cannot replicate it (simillar to this issue, but I used 2 nodes and deleted and reatached outgoing connection)