Fix a test failure with readline 8.1

[antonio-rojas]

readline 8.1 seems to print more escape characters in raw mode, which causes a test failure in misc/trace.py

File "/usr/lib/python3.9/site-packages/sage/misc/trace.py", line 66, in sage.misc.trace.trace
Failed example:
    print(s.before[s.before.find(b'--'):].decode())
Expected:
    --...
    ipdb> c
    2 * 5
Got:
    --Call--
    > <CSI-0;32m>/usr/lib/python3.9/site-packages/sage/arith/misc.py<CSI-0m>(2422)<CSI-0;36m>factor<CSI-0;34m>()<CSI-0m>
    <CSI-0;32m>   2420 <CSI-0;31m><CSI-0;34m><CSI-0m><CSI-0m>
    <CSI-0m><CSI-0;32m>   2421 <CSI-0;31m><CSI-0;34m><CSI-0m><CSI-0m>
    <CSI-0m><CSI-0;32m>-> 2422 <CSI-0;31m><CSI-0;32m>def<CSI-0m> <CSI-0m>factor<CSI-0m><CSI-0;34m>(<CSI-0m><CSI-0m>n<CSI-0m><CSI-0;34m>,<CSI-0m> <CSI-0m>proof<CSI-0m><CSI-0;34m>=<CSI-0m><CSI-0;32m>None<CSI-0m><CSI-0;34m>,<CSI-0m> <CSI-0m>int_<CSI-0m><CSI-0;34m>=<CSI-0m><CSI-0;32m>False<CSI-0m><CSI-0;34m>,<CSI-0m> <CSI-0m>algorithm<CSI-0m><CSI-0;34m>=<CSI-0m><CSI-0;34m>'pari'<CSI-0m><CSI-0;34m>,<CSI-0m> <CSI-0m>verbose<CSI-0m><CSI-0;34m>=<CSI-0m><CSI-0;36m>0<CSI-0m><CSI-0;34m>,<CSI-0m> <CSI-0;34m>**<CSI-0m><CSI-0m>kwds<CSI-0m><CSI-0;34m>)<CSI-0m><CSI-0;34m>:<CSI-0m><CSI-0;34m><CSI-0m><CSI-0;34m><CSI-0m><CSI-0m>
    <CSI-0m><CSI-0;32m>   2423 <CSI-0;31m>    """
    <CSI-0m><CSI-0;32m>   2424 <CSI-0;31m>    <CSI-0m>Return<CSI-0m> <CSI-0m>the<CSI-0m> <CSI-0m>factorization<CSI-0m> <CSI-0m>of<CSI-0m><CSI-0;31m> <CSI-0m><CSI-0;31m>`<CSI-0m><CSI-0;31m>`<CSI-0m><CSI-0m>n<CSI-0m><CSI-0;31m>`<CSI-0m><CSI-0;31m>`<CSI-0m><CSI-0;34m>.<CSI-0m>  <CSI-0m>The<CSI-0m> <CSI-0m>result<CSI-0m> <CSI-0m>depends<CSI-0m> <CSI-0m>on<CSI-0m> <CSI-0m>the<CSI-0m><CSI-0;34m><CSI-0m><CSI-0;34m><CSI-0m><CSI-0m>
    <CSI-0m>
    <CSI-?2004h>ipdb> c
2 * 5CSI-?2004l>
    <BLANKLINE>
**********************************************************************

The trace command being tested here seems to work fine when run manually.

CC: @kiwifb @mkoeppe @isuruf @EmmanuelCharpentier

Component: packages: standard

Author: Antonio Rojas

Branch/Commit: e294182

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/31063

[antonio-rojas]

Branch: u/arojas/fix_a_test_failure_with_readline_6_1

[sagetrac-git]

Commit: e294182

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

e294182

Fix tests with readline 6.1

[antonio-rojas]

Author: Antonio Rojas

[mkoeppe]

Reviewer: Matthias Koeppe

[vbraun]

Changed branch from u/arojas/fix_a_test_failure_with_readline_6_1 to e294182