Fixes some typos as found by codespell run on the code. In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc. Follow-up commits will take care of them. Refs: https://github.com/scylladb/scylladb/issues/16255 Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>