Bump helix to version 25.01

[papertigers]

There's a new version of helix with a bunch of nice features.

Builds successfully:

Do you wish to continue anyway? (y/n) y
===== User elected to continue after prompt. =====
-- Cleaning up
--- Removing temporary install directory /tmp/build_omnios/helix-25.01/ooce_editor_helix_pkg
--- Cleaning up temporary manifest and transform files
Done.
Time: ooce/editor/helix - 0h4m40s

Note I pulled the source tar.xz and used site.sh to point the build system at it since I can't modify the omnios mirror web server.