Add JohnCSimon back to members list

[JohnCSimon]

thanks for having me back

[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/all':
      Adding member 'JohnCSimon' with member role
    📝 Editing team 'rust-lang/triage':
      Adding member 'JohnCSimon' with member role
    📝 Editing team 'rust-embedded/risc-v':
      Adding member 'rmsyn' with member role

[apiraino]

(for context, as discussed on Zulip: @JohnCSimon just missed the GitHub notification from #2609 )

[jieyouxu]

Asked in #t-release/triage > Removed from triage group @ 💬