Update of gimp-netpbm2gimp-plugins to Netpbm 11.06.01

This is an update of gimp-netpbm2gimp-plugins to correspond to the 11-Apr-2024 release of the Netpbm utilities.

No new utilities have been added recently to Netpbm, but there have been a number of upstream bug fixes and feature enhancements made to various utilities. See the Netpbm change log for a list of everything that's changed in Netpbm v11.06.01 (and all other versions in the "Advanced" release).