Fix p_group_cohomology doctest errors

[mkoeppe]

(from #30787)

Depends on #30787

CC: @simon-king-jena @dimpase @jhpalmieri @tscrim

Component: packages: optional

Issue created by migration from https://trac.sagemath.org/ticket/34333

[jhpalmieri]

comment:1

I have attached the failures that I see.

[jhpalmieri]

Attachment: p_grp_cohom_tests.log

[tscrim]

comment:2

There is also the one within the Sage library:

sage -t --warn-long 62.5 --random-seed=230138939486715312795148381621394057005 src/sage/tests/modular_group_cohomology.py
**********************************************************************
File "src/sage/tests/modular_group_cohomology.py", line 55, in sage.tests.modular_group_cohomology
Failed example:
    ascii_art(H.bar_code('LowerCentralSeries')[2])# optional - p_group_cohomology
Expected:
        *
      *-*
      *-*
    *
Got:
      *-*
      *-*
      *-*
      *-*
    *
**********************************************************************
1 item had failures:
   1 of  18 in sage.tests.modular_group_cohomology
    [17 tests, 1 failure, 3.71 s]

[jhpalmieri]

comment:3

I don't know the math well enough to be able to do the computations myself, but I hope that Simon (or his coauthor) can check the calculations arising in

sage: from pGroupCohomology import CohomologyRing
sage: H = CohomologyRing(27,4)
sage: H.make()
sage: BC = H.bar_code('LowerCentralSeries')
sage: BC.show()
...
sage: BC.data()
...

and in particular the ascii_art error here.