File _multibuild of Package mumps

<multibuild>
  <package>serial</package>
  <package>openmpi4</package>
  <package>openmpi5</package>
  <package>mvapich2</package>
  <package>scotch-serial</package>
  <package>scotch-openmpi4</package>
  <package>scotch-openmpi5</package>
<!-- <package>scotch-mvapich2</package> -->
</multibuild>