Rather than having valid-narinfo? evaluate to #t if
%allow-unauthenticated-substitutes? is set to #t, just use (const #t) for
valid-narinfo? when %allow-unauthenticated-substitutes? is set to #t. This
will allow moving valid-narinfo? in to a (guix substitutes) module.
* guix/scripts/substitute.scm (process-query, process-substitution): Change
the authorized? argument to lookup-narinfo and lookup-narinfos/diverse based
on %allow-unauthenticated-substitutes?.
(valid-narinfo?): Remove use of %allow-unauthenticated-substitutes?.
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