Fix CRT Credential missing dependency

[lfoppiano]

1. aws login (@parismic method) is acktually very standard. Not only is standard, it's better than using access key credentials.
2. since warc2zip needs to work on s3 regardless their auth system, we add the dependency.
3. Eventuall warcio[s3] may support it in the future, but adding botocore[crt] may have additional unexpected impacts (e.g. it overrides other mechanism used by default in botocore3) -- I did not investigate those, just mentioning them
4. The README.MD explains more clearly that botocore[crt] is required for aws login auth mechanism

This fixes #1

[lfoppiano]

I've merged main into there, so @parismic you can test anything you want :-)