Bug#1028547: Firmware is not udpkg -i before hardware detection

[Jamie Wilkinson <jaq@debian.org>]

I think I've figured out why we see these errors.

I restarted an Expert mode installation with the latest nightly DI
https://cdimage.debian.org/cdimage/daily-builds/daily/arch-latest/amd64/iso-cd/
dated
2023-03-07 04:13 size 758M

I ran through the installation to "load installer components from
installation media", then opened the terminal on tty2.

I changed into /cdrom/firmware and used `udpkg -i *.deb` to install
everything.  There were many warnings about missing tools which are
now lost off the console.

I manually ran `modprobe mt7921e` and returned without error.  `dmesg`
has the following in the tail:

mt7921e: firmware: direct-loading firmware
mediatek/WIFI_MT7961_patch_mcu_1_2_hdr.bin
mt7921e: HW/SW Version: 0x8a108a10, Build Time: 20230117170855a
mt7921e: firmware: direct-loading firmware mediatek/WIFI_RAM_CODE_MT7961_1.bin
mt7921e: HW/SW Version: ____010000, Build Time: 20230117170942
mt7921e: firmware: direct-loading firmware mediatek/WIFI_RAM_CODE_MT7961_1.bin
mt7921e: wlp3s0: renamed from wlan0

I then returned to the menu on tty1 and detected network hardware, and
the installer now sees the WiFi interface.

So I think the problem here is that the firmware udebs are not
unpacked before hardware detection starts.