Move test executables from /sbin/ to /bin/

Install the test executables into /sbin/ seems like a strange use of that path, which the Linux Filesystem Hierarchy defines as:

/sbin should contain only binaries essential for booting, restoring, recovering, and/or repairing the system in addition to the binaries in /bin.

In addition, conda activate does not include ${CONDA_PREFIX}/sbin/ in $PATH so the test executables have to be manually located.

Given those points, it is reasonable to install the test scripts into /bin/ (${CMAKE_INSTALL_BINDIR}) instead?

This presume that the test scripts are still being installed now that ctest is configured for this project.