Reconstitute WG-allocators

[nia-e]

cc @Amanieu and generally @rust-lang/libs. happy to move more ppl into here from alumni if they're interested, but this should be a good start for now

[nia-e]

cc @N1ark since this fixes your entry

[N1ark]

oops, yes ty

[github-actions]

Dry-run check results

[WARN  rust_team::sync] sync-team is running in dry mode, no changes will be applied.
[INFO  rust_team::sync] synchronizing crates-io
[INFO  rust_team::sync] synchronizing github
[INFO  rust_team::sync] 💻 Team Diffs:
    📝 Editing team 'rust-lang/wg-allocators':
      Adding member 'N1ark' with member role
      Adding member 'clarfonthey' with member role
      Adding member 'nia-e' with member role
      Deleting member 'scottjmaddox'
      Deleting member 'CAD97'
      Deleting member 'Lokathor'
      Deleting member 'TimDiekmann'
      Deleting member 'Wodann'
    💻 Org membership Diffs:
    ❌ Removing the following members from `rust-lang`:
      - Lokathor
      - TimDiekmann
      - Wodann
      - scottjmaddox

[Amanieu]

@rust-lang/wg-allocators If any of the existing members are interested in staying on the working group, please leave a message in this thread!

[TimDiekmann]

Unfortunately, I don't have the capacity to contribute 🙁