Remove broken experimental package scons #30155
Description
It is unused and not compatible with python3. It was made experimental in #28687.
https://github.com/mkoeppe/sage/runs/876312062
[scons-1.2.0] ****************************************************
[scons-1.2.0] Package 'scons' is currently not installed
[scons-1.2.0] No legacy uninstaller found for 'scons'; nothing to do
[scons-1.2.0] File "setup.py", line 336
[scons-1.2.0] mode = ((os.stat(file)[stat.ST_MODE]) | 0555) & 07777
[scons-1.2.0] ^
[scons-1.2.0] SyntaxError: invalid token
[scons-1.2.0] Error installing scons
CC: @jhpalmieri @dimpase @fchapoton
Component: packages: experimental
Author: Matthias Koeppe, John Palmieri
Branch/Commit: 41a3e66
Reviewer: Dima Pasechnik
Issue created by migration from https://trac.sagemath.org/ticket/30155