Currently package-locks are conditionalized in the build with
:SB-PACKAGE-LOCKS, but I've no idea if anyone actually actively tests that
the build still works without them.
Unless there are objections I would like to remove the conditionalization.
I'm not so sure if :SB-PACKAGE-LOCKS should be removed from *FEATURES*
too: perhaps after a month or two?
-- Nikodemus Schemer: "Buddha is small, clean, and serious."
Lispnik: "Buddha is big, has hairy armpits, and laughs."