Remove @SuppressWarnings("deprecation") used in commons-exec upgrade from 1.3 to 1.4.0

[vorburger]

The build failures due to a bunch of new @Deprecated in the commons-exec upgrade from 1.3 to 1.4.0 in #179, which I would like to adopt in order to fix #9, seem to be a little peskier (PITA) to address than I initially thought.

In the interest of time, I'll add some @SuppressWarnings("deprecation") for now, in order to be able to #187 sooner rather than later.

The goal of resolving this issue will be to completely remove those @SuppressWarnings("deprecation") again.

This may be required for an eventual future commons-exec upgrade from 1.4.0 to a 1.5.0 or 2.0.0 if they ever release that (and remove their @Deprecated as part of that). Which is a lot of if... 🤣

@mosesn or gsylvie@ or @cardamon or @Blanco27 or @duttonw your contributions for this are most welcome!