Remove reference to old Python pygments formatters module

We used to have a pygments fork that adds a custom formatters, namely redhtmltab [1]. This is fork is no more in ThirdParty [2] and not used in Superbuild [3] (it uses upstream pypi).

Also, this seems to adress the crash described at #22849 (closed)

• [1] https://gitlab.kitware.com/third-party/pygments
• [2] see 649ca4e5
• [3] https://gitlab.kitware.com/paraview/common-superbuild/-/blob/master/versions.cmake