For claude, ignore no runtime for offline shm reading

piker/data/_sharedmem.py

@@ -520,7 +520,10 @@ def open_shm_array(
 
     # "unlink" created shm on process teardown by
     # pushing teardown calls onto actor context stack
-    stack = tractor.current_actor().lifetime_stack
+    stack = tractor.current_actor(
+        err_on_no_runtime=False,
+    ).lifetime_stack
+    if stack:
         stack.callback(shmarr.close)
         stack.callback(shmarr.destroy)
 
@@ -607,7 +610,10 @@ def attach_shm_array(
         _known_tokens[key] = token
 
     # "close" attached shm on actor teardown
-    tractor.current_actor().lifetime_stack.callback(sha.close)
+    if (actor := tractor.current_actor(
+        err_on_no_runtime=False,
+    )):
+        actor.lifetime_stack.callback(sha.close)
 
     return sha