[web] fix css file generation permission bug (closes #17143773)
PropertySheet.process_resource() uses mkstemp which enforce a 0600 mode on the
output file, which is not the file permission we want for css files.
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/python-cubicweb-documentation/html/index.html
Files: /usr/share/doc/python-cubicweb-documentation/html/*