xsdk: enable sundials@4.1.0 for xsdk@develop (#10989)
xsdk: enable sundials@4.1.0 for xsdk@develop (#10989)

- disable sundials varaiant for dealii and mfem - as they are incomatible with sundials@4.1.0
iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack