simplify totp verification code

[ssinghi]

Do not create unnecessary arrays.

Code refactor.

[mdp]

This fails currently, but I'm open to the cleanup. The main issue is the use of a non time constant algorithm to check the OTP. Although a timing attack is probably completely infeasible in this case, it's worth making sure all our checks are time constant.

[ssinghi]

I have updated the code to be time constant as well as fixed the totp related failing test. But can't figure out why the truffleruby-head test are failing, seems unrelated to my changes.

[BertramScharpf]

I had almost the same idea. But instead of waiting two years for a merge, I opened my own project. In case you're interested, it's called BertramScharpf/ruby-popt.

[mdp]

Sorry, this looks like an rspec issue. I fixed it on 'main' but I'm going to close this in favor of the refactor in #140. Thanks for the PR though.