editors/sly: Update to the latest commit (20230523)

Since no official version has been released since 1.0.43, update to the latest
commit (after some tests). Tweak the version number to avoid bumping PORTEPOCH.

Lots of small changes, including fixes and customization enhancements to the
REPL, adaptations for future Emacs version, a bunch of fixes for ABCL and clasp.

Changelog: https://github.com/joaotavora/sly/compare/eb67be96...e6bc13d9

PR: 271652