sysutils/eza: Update to 0.18.19

Remove shell completion options, install completions.
Use shipped manual page instead of generating with pandoc,
remove MANPAGES option.
Use DIST_SUBDIR.

Changelog: https://github.com/eza-community/eza/releases/tag/v0.18.19

PR: 279874
Approved by: Submitter is maintainer