Eh, I have to disappoint you there. Problem is solved for now, but Packman discontinued from Jan 1st 2027, but here's your chance! just happened. And the broadcom-wl package also pulls in the kmp which *should always match the running kernel version.
BUT … the problem will be solved by buying some linux supported USB Wifi adapter. Some locals I support have done so, and relieved them from having to go through all kinds of hoops, since their MacBooks don’t have ethernet either. In the past they used to manually download the broadcom stuff on a USB key over another machine, then on the MacBook install manually from the USB key…