shells/fish: update to 3.7.1 and fix Makefile

- Update to fish 3.7.1.
- Remove zfs feature check patch; included upstream.
- Remove post install step to strip binaries; binaries are stripped
  durting install.
- Add post install steps to remove documentation and/or manual pages if
  DOCS and/or MANPAGES are not enabled. Be default fish always installs
  documentation and manual pages.

PR:		278468
Approved by:	asomers (maintainer)