Fixes inducers breaking when trying to charge a PDA/Modular Computer (#83087)

## About The Pull Request
Fixes #83035 - attached_circuit is not guaranteed to exist & we should
just pass the parent in that case.
## Why It's Good For The Game
Inducers no longer break permanently due to this issue.
## Changelog
🆑 ShizCalev
fix: Inducers no longer break completely after trying to charge a PDA
with them.
/🆑

---------

Co-authored-by: Ghom <42542238+Ghommie@ users.noreply.github.com>

code/datums/components/shell.dm

@@ -173,7 +173,7 @@
 
 	if(istype(item, /obj/item/inducer))
 		var/obj/item/inducer/inducer = item
-		INVOKE_ASYNC(inducer, TYPE_PROC_REF(/obj/item, attack_atom), attached_circuit, attacker, list())
+		INVOKE_ASYNC(inducer, TYPE_PROC_REF(/obj/item, attack_atom), attached_circuit || parent, attacker, list())
 		return COMPONENT_NO_AFTERATTACK
 
 	if(attached_circuit)