add working group for Field Projections

[BennoLossin]

Cc @tmandry @Nadrieril @dingxiangfei2009

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[BennoLossin]

ugh why is the github default a merge...

[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:
    ➕ Creating team:
      Org: rust-lang
      Name: field-projections
      Description: Managed by the rust-lang/team repository.
      Privacy: closed
      Members:
        BennoLossin: member
        Nadrieril: member
        dingxiangfei2009: member
        tmandry: member
    📝 Editing team 'rust-lang/all':
      Adding member 'BennoLossin' with member role
    📝 Editing team 'rust-lang/inside-rust-reviewers':
      Adding member 'BennoLossin' with member role
    📝 Editing team 'rust-lang/leads':
      Adding member 'BennoLossin' with member role