A user (on 7.17.7) reported to me a situation where they were attempting to delete a snapshot and would get the log message `deleting snapshots [snapshot-test] from repository [my-snapshots]` but then no further messages at `INFO` or above; enabling some internal logging indicated some low-level timeouts:

```
[DEBUG][com.amazonaws.latency    ] [instance-0123456789] MaxRetriesExceeded=[true], ServiceName=[Amazon S3], ServiceEndpoint=[https://REDACTED/], Exception=[java.net.SocketTimeoutException: Read timed out, java.net.SocketTimeoutException: Read timed out, java.net.SocketTimeoutException: Read timed out, java.net.SocketTimeoutException: Read timed out],...
```

This was enough for the user to go and investigate some performance issues in their repository, but I find the lack of logging concerning. Eventually the cluster state contains no ongoing snapshot deletion, but there is nothing in the logs to indicate that anything didn't work. The deletion API request had already timed out by this point so we can't return an error that way either. I'm opening this issue to make sure we investigate the missing logging.
server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java
for (RepositoryShardId shardId : canBeUpdated) {
                                final ShardId sid = entry.shardId(shardId);
                                final ShardSnapshotStatus updated = shardAssignments.get(sid);
                                if (updated == null) {
                                    
                                    assert currentState.routingTable().hasIndex(sid.getIndex()) == false
                                        : "Missing assignment for [" + sid + "]";
                                    updatedAssignmentsBuilder.put(sid, ShardSnapshotStatus.MISSING);
                                } else {
                                    if (updated.isActive()) {
                                        markShardReassigned(shardId, reassignedShardIds);
                                    }
                                    updatedAssignmentsBuilder.put(sid, updated);
                                }
                            }
                            final SnapshotsInProgress.Entry updatedEntry = entry.withShardStates(updatedAssignmentsBuilder.build());
                            snapshotEntries.add(updatedEntry);
                            changed = true;
                            if (updatedEntry.state().completed()) {
                                newFinalizations.add(entry);
                            }
                        }
                    }
                } else {
                    
                    
                    newFinalizations.add(entry);
                    snapshotEntries.add(entry);
                }
            }