The concept does not apply.
Think about it. The
search items in
/etc/resolv.conf control, for some DNS client libraries, how a non-fully-qualified domain name becomes a fully qualified domain domain name for use in the actual DNS protocol (to which the concept also does not apply). It would be infinite recursion for the qualification process to apply to itself.
Not all DNS client libraries and name qualification procedures use
/etc/resolv.conf in the first place, of course. Of those that do, I am unaware of any that mind the presence or absence of a trailing dot in the search path suffixes, or where it makes any concrete difference.
You can look at this as the strings here being always fully qualified, whether a dot is present or no. But it is better to look at this as the concept of qualification not applying to one of the very mechanisms that translate non-fully-qualified names, because the idea of non-fully-qualified names exists in the layer above that mechanism.