net/wifi-firmware-iwlwifi-kmod: update firmware to 20251021

Intel firmware for BE200 ("bz" chipsets) requires more modern firmware
than we provide. [1]
The firmware file for iwlwifi-so-a0-gf4-a0 was missing in a recent
version; we only had the pnvm file. [2]

Update the Intel iwlwifi firmware to the latest tree
which brings a few changes:
(1) on linux-firmware.git the firmware got moved into a subdirectory

so we need to strip that path before installing as the driver
still expects the firmware in the top-level directory.

(2) the "bz" firmware gets bumped to 101, we keep the old version for

14.3-R around as well.

(3) while the other files keep their revisions, Intel may have updated

them with rebuilds.  This is hard to discover given not only the
hashes but also the paths have changed in distinfo.

(4) we now generate the firmware list from the WHENCE file in

linux-firmware.git given the driver firmware name creation is too
dynamic.  This adds some extra firmware files we did not have
before.  See files/extract-fw-list.sh.

PR: 290808
Reported by: dch [1], Fotis Zabaras (fotis zabaras.eu) (and others) [2]
Reviewed by: jrm
Differential Revision: https://reviews.freebsd.org/D53681