remove two unused hooks

move walk-dir to extra/io/paths

core/io/files/files.factor

@@ -141,37 +141,6 @@ C: <pathname> pathname
 
 M: pathname <=> [ pathname-string ] compare ;
 
-HOOK: library-roots io-backend ( -- seq )
-HOOK: binary-roots io-backend ( -- seq )
-
-: find-file ( seq str -- path/f )
-    [
-        [ path+ exists? ] curry find nip
-    ] keep over [ path+ ] [ drop ] if ;
-
-: find-library ( str -- path/f )
-    library-roots swap find-file ;
-
-: find-binary ( str -- path/f )
-    binary-roots swap find-file ;
-
-<PRIVATE
-: append-path ( path files -- paths )
-    [ path+ ] with map ;
-
-: get-paths ( dir -- paths )
-    dup directory keys append-path ;
-
-: (walk-dir) ( path -- )
-    dup directory? [
-        get-paths dup % [ (walk-dir) ] each
-    ] [
-        drop
-    ] if ;
-PRIVATE>
-
-: walk-dir ( path -- seq ) [ (walk-dir) ] { } make ;
-
 : file-lines ( path -- seq ) <file-reader> lines ;
 
 : file-contents ( path -- str )