lockfree CVE incoming

[jayvdb]

c.f. rustsec/advisory-db#2214

https://github.com/wyatt-herkamp/lock_freedom is an active fork, however I will also add lfqueue as another recommended alternative.

IMO it would be a good idea for you to replace lockfree in your deps & README comparison with lock_freedom.

[DiscordJim]

Dear @jayvdb, thank you for making me aware of this. I will be making these changes and will open a PR soon.