Update SEP statuses

[chowbao]

• Update SEP readme with the current statuses of SEPs committed in the repo
• New status names
  • Active --> Final
  • Rejected --> Abandoned

[chowbao]

TODO: will update the old SEPs in draft as I read through the threads and see if they should be revived or abandoned

• Remove Active --> Final
• Separate Rejected --> Abandoned changes into separate PR (update readme)

[leighmcculloch]

If rejected is being replaced with abandoned (which I support), the README docs describing the statuses should be updated. Fwiw I think it's worth doing that change alone in a separate PR, so that the what and why are hyperfocused on one decision. One decision, one PR, is easier for folks to track why something is happening, and debate it in isolation of other decisions.

[github-actions]

This pull request is stale because it has been open for 30 days with no activity. It will be closed in 30 days unless the stale label is removed.