mail/maildrop: Fix INOTIFY option

• FreeBSD 14.5 and up include inotify implementation in libc, so update checks to not depend on the ports implementation ion this case
• When using the ports provided libinotify link using the dynamic library
• Also add one file that needs patching for a successful build

While here, pet portclippy/portfmt.

Reported by: Ewout1 (Excite/BlueTie) <ewout1@bluetiehome.com> (via mailing list)
MFH: 2026Q3