Compilation fails with GCC 13 standard library

[berquist]

In file included from /home/eric/development/forks/sst/sst-core/src/sst/core/unitAlgebra.h:17,
                 from /home/eric/development/forks/sst/sst-core/src/sst/core/unitAlgebra.cc:14:
/home/eric/development/forks/sst/sst-core/src/sst/core/decimal_fixedpoint.h:44:22: error: ‘uint32_t’ does not name a type
   44 |     static constexpr uint32_t storage_radix      = 100000000;
      |                      ^~~~~~~~
/home/eric/development/forks/sst/sst-core/src/sst/core/decimal_fixedpoint.h:21:1: note: ‘uint32_t’ is defined in header ‘<cstdint>’; did you forget to ‘#include <cstdint>’?
   20 | #include <limits>
  +++ |+#include <cstdint>
   21 | #include <sstream>

This is with Clang 15, but it still uses the GNU standard library.

[berquist]

Done in #973.