ADDED: el_set/2 prompt_marks(Boolean)

Updates libedit and xpce.  Turns the OSC 133 prompt marks off for a
terminal that would print them rather than read them.  They are on by
default.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T13zyETRgTwZhjk383aj5n

Author: JanWielemaker