le(4): Update depreciation notice

This driver was in fact not removed prior to FreeBSD 15.0.

Approved by: re (cperciva)
Sponsored by: The FreeBSD Foundation

(cherry picked from commit e4d6433e9c0379e164ff50ce829b5b1c0716bcb1)
(cherry picked from commit 59ba7278499f0ee20fd9c43a34bb2b72ae57dcbb)