Memory manager deferred-length character array segfault with gfortran debug version

[langevin-usgs]

It appears gfortran (11.3.0) has an issue storing a pointer to a deferred-length character array. A recent mf6 pull request (#966) implemented the checking in of character arrays to the memory manager; however, this fails with a segmentation fault when running with the debug version of gfortran. Program runs in release mode with gfortran, which is why CI did not pick up on the issue, but use of the memory to get a pointer to a character array does not work. Probably need to roll this back until and reactivate if compiler issue is fixed.

A bug report has been filed with gnu to report the issue here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106317