Deprecate and remove `clap_complete_fig`?

[epage]

Fig is sunsetted, see https://news.ycombinator.com/item?id=39683889

[epage]

See

• https://github.com/denoland/deno/discussions/22903
  • Suggests waiting for September
• https://github.com/ajeetdsouza/zoxide/discussions/757

[pksunkara]

I would propose doing the deprecation now and removing it later after September.