Rust-analyzer depends on anymap 1.0.0-beta.2

[gigaroby]

This appears to be unmaintained and contain soundness issues: https://rustsec.org/advisories/RUSTSEC-2021-0065.html.

See also chris-morgan/anymap#37

[lnicola]

Looks like the soundness issue was fixed in the version we're using. It might be nice to move off anymap, but it doesn't seem terribly urgent.

[Veykril]

We should move off of it I think, it's easy enough to self implement this, especially since we don't need the entire API surface either

[shogo-nakano-desu]

Hi, can I try to work on this issue?

[lnicola]

@shogo-nakano-desu go ahead!

[lnicola]

Port added in #15618.

Now we're not going to know about any anymap CVEs, but they're still going to affect us 😬.