[etwist] remove no-longer-necessary uicache cleaning
It was done before we were actually up, which means it could be too
eager when combined with #6893185.
Closes #6893247.
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html