perf(lookup): defer consult-xref
perf(lookup): defer consult-xref

`consult-xref` is autoloaded anyway. There are some packages that
require `xref` (such as lispy through requiring etags) so without
deferring, loading those packages may cause `consult.el` to be loaded.

hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs