For the time being rtw88(4) and rtw89(4) need to limit memory to the
lower 4G (see their man pages) in order to work properly.
Set the sysctl on the release media.
I believe the proper way to handle this in the future (with more time)
would be to have the firmware port to install a file into
/boot/loader.conf.d/ but this would unlikely make it for 14.2-R in time.
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