- fail if all retries failed.
- run `dpkg --configure -a` after an aborted slow attempt.
```
Selecting previously unselected package libsys-hostname-long-perl.
Error: slow server, retry
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
[...]
```
Bug: https://github.com/curl/curl/pull/21107#issuecomment-4163506100
Follow-up to 5172ba5475#21107Closes#21181