Remove undocumented GifImagePlugin._save_netpbm - #9901

Remove undocumented GifImagePlugin._save_netpbm#9901

akx wants to merge 2 commits into

python-pillow:mainpython-pillow/Pillow:mainfrom

akx:no-save-netpbmakx/Pillow:no-save-netpbmCopy head branch name to clipboard