Add ada4a to the "Clippy" team

[samueltardieu]

Incoming from the "Clippy contributors" team.

[flip1995]

Welcome to the (main) team @ada4a! 🎉 Please also approve this PR to accept the team invitation :)

[ada4a]

Thank you @samueltardieu :)

[github-actions]

Dry-run check results

[WARN  sync_team] sync-team is running in dry mode, no changes will be applied.
[INFO  sync_team] synchronizing crates-io
[INFO  sync_team] synchronizing github
[INFO  sync_team] 💻 Team Diffs:
    📝 Editing team 'rust-lang/clippy':
      Adding member 'ada4a' with member role
    📝 Editing team 'rust-lang/clippy-contributors':
      Deleting member 'ada4a'

[samueltardieu]

Friendly ping @rust-lang/team-repo-admins, I don't know if you get notifications, and #1758 is blocked so we can't merge by ourselves.