In modified files [0] we can find a note that the
Expect script is time-sensitive when combined with
number of programs (e.g. ksh), and to discard or
ignore keystrokes that come "too fast" after
prompts after prompts.
The solution is to use the conservative mode.
[0]: https://src.fedoraproject.org/tests/shell/blob/main/f/tests/login/ssh.exp
Create plan for each supported shell, pick relevant tests.
Remove Makefile and PURPOSE files, they are no more necessary.
Group tests and plans, each under a dedicated directory.
Add tags to allow selecting tests for running in a container.
