Fix symbolics doctest after #31873

[mkoeppe]

failing in 9.5.beta0 with sage -t

as noted in #32386 comment:104

CC: @dimpase @mwageringel

Component: symbolics

Author: Matthias Koeppe

Branch/Commit: 2a6ff9d

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/32461

[mkoeppe]

Branch: u/mkoeppe/fix_symbolics_doctest_after__31873

[mkoeppe]

Commit: 2a6ff9d

[mkoeppe]

New commits:

2a6ff9d

src/doc/en/prep/Calculus.rst: Add a missing '# long time'

[mkoeppe]

Author: Matthias Koeppe

[dimpase]

Reviewer: Dima Pasechnik

[dimpase]

comment:3

lgtm

[mkoeppe]

comment:4

Thanks

[mwageringel]

comment:6

Thanks.

[vbraun]

Changed branch from u/mkoeppe/fix_symbolics_doctest_after__31873 to 2a6ff9d