We can remove the execdir mailman list
Apparently there is a mailman list named execdir: https://lists.torproject.org/cgi-bin/mailman/listinfo/execdir
It has no people on it, because it's never been used.
(There is a postfix alias named execdir@tpo, but that's a different thing.)
We should feel free to remove the execdir mailman list, to keep things tidy.