Merge pull request #14186 from drwells/misc-header-cleanup

diff --cc include/deal.II/base/index_set.h
index f4d09b1dffdc95b7fb12e483f576fd62980c232c,a77f95ce0fea7d85b1678f361ba0c4aa4fbed7d7..500e19260aac3084303eaed1ccf4439f44fd0e0f
--- 1/include/deal.II/base/index_set.h
--- 2/include/deal.II/base/index_set.h
+++ b/include/deal.II/base/index_set.h
@@@ -19,9 -19,7 +19,8 @@@
  #include <deal.II/base/config.h>
  
  #include <deal.II/base/exceptions.h>
 +#include <deal.II/base/mpi_stub.h>
  #include <deal.II/base/mutex.h>
- #include <deal.II/base/utilities.h>
  
  DEAL_II_DISABLE_EXTRA_DIAGNOSTICS
  #include <boost/container/small_vector.hpp>