MPI_Type_free still called for bool

https://github.com/boostorg/mpi/commit/c5270b066f6f810b2fa184650a4215bb5c83ba27 added an explicit MPI_Type_free for the MPI_Type_commit on bool.
When the bool type was converted to a built-in type (MPI_CXX_BOOL/MPI_C_BOOL), the explicit free was not removed.

My debugger found this with a `__debugbreak()` throw in Kernel32 in a debug build with MSMPI 10.1.3 and boost 1.91.0 when destructing `boost::mpi::environment` & calling `mpi_datatype_map::clear`.
Release builds seem to run ok, but that may be just because the program is already headed down and this is one of the last destructors to run.