superlu-dist: Upgrade to 6.1.0.

* gnu/packages/patches/superlu-dist-awpm-grid.patch: New file.
* gnu/packages/maths.scm (superlu-dist)[source]: Upgrade to 6.0.0.  Remove
extraneous 'use-modules' in snippet.
[build-system]: Change to cmake-build-system.
[propagated-inputs]:   Replace pt-scotch with pt-scotch32 to match integer
sizes.  Add "parmetis" input, from pt-scotch32.  Move lapack to ...
[inputs]: ...here.  Add openblas and combinatorial-blas.
[arguments]: Replace 'configure' phase with #:configure-flags.  Add
'set-c++-standard' and 'omp-setup' phases.  Remove
'create-install-directories, 'check', and 'install' phases, which are now
handled by cmake.
* gnu/local.mk (dist_patch_DATA): Add patch.