* Update config for Buildroot 2023.02
* Use Buildroot's version of the rtl8821cu package
Buildroot provides a newer driver for the RTL8821CU based chipsets
provided by https://github.com/morrownr/8821cu-20210118.
* Pass argument when verifying partition table
This also avoids running into a segmentation fault in the current
version of sgdisk.
* Remove obsolte GRUB2/NetworkManager patches
* Bump buildroot
* buildroot 90aa1a6daa...4832525e6c (4596):
> package/runc: add support for CGroup device permission updates
> package/network-manager: fix build with -Dmodem_manager=false
> package/dbus-broker: bump to release 33
> package/iptables: Allow to use iptables with nf_tables backend
> package/brcmfmac_sdio-firmware-rpi: bump to latest version
> package/linux-firmware: Deploy fewer Intel WiFi 22000 series variants
> package/linux-firmware: Add more Intel WiFi 22000 series variants
> package/linux-firmware: Add Broadcom BNX2 firmware
> package/rpi-firmware: bump version to 1.20230106
> Update for 2023.02-rc2
* Use Ubuntu 22.04 for CI checks
* Bump xe-guest-utilities to 7.33.0
* Remove unnecessary shellcheck ignore for xe-guest-utilities
* Address new buildroot check-packages issues
