Clean up LWC algorithms based on final round

[jvz]

https://csrc.nist.gov/News/2021/lightweight-crypto-finalists-announced

Looks like Gimli got nixed as I thought it might. That can be removed now. ISAP made it to the final round as well, so perhaps that'd be a good replacement. Some other potential options to consider:

• PHOTON-Beetle
• Elephant
• Romulus

Other ciphers in the final round look interesting, but they only offer AEAD modes.