ci: alternate local sshd port (-P) end-to-end test

[JeremyTubongbanua]

closes: #375

- What I did

• added an end-to-end test to test the -P flag

- How I did it

I ran the following in sshnp:

echo "Port 55" | sudo tee -a /etc/ssh/sshd_config
sudo service ssh restart
SSHNP_COMMAND="$HOME/.local/bin/sshnp -f @8incanteater -t @8052simple -d 6116339046140 -h @rv_am -s id_ed25519.pub -P 55 -v > logs.txt"

- How to verify it

tests passing in GHA

- Description for the changelog