(GitHub Action) Improve map and map-ref. (#209)

This commit was copied from the master branch.

Commit: 64a95bc
Author: okamsn <28612288+okamsn@users.noreply.github.com>
Date: 2024-09-11 23:05:21 +0000

Improve `map` and `map-ref`. (#209)

- Check as we go instead of using `seq-uniq` immediately, which tests have shown
  to always faster for the tested 10, 100, and 1000 entries.

- Allow `unique` to be evaluated at run time.  Optimize when we know
  when it is `nil` or `non-nil` at compile time.

- Clarify Org docs.

See also issue #179. Closes #179.

Author: github-actions[bot]