fix: remove unreachable panic; return instead (#490)

This error caused chainhook to crash today. This route can happen if a
predicate is completed, but we're still waiting on block confirmations
for fully expire the predicate, and then the user deletes the predicate.

components/chainhook-cli/src/service/mod.rs

@@ -955,7 +955,10 @@ pub fn set_confirmed_expiration_status(
                 return;
             }
         },
-        None => unreachable!("found no status for predicate: {}", predicate_key),
+        None => {
+            // None means the predicate was deleted, so we can just ignore this predicate expiring
+            return;
+        }
     };
     update_predicate_status(
         predicate_key,