Remove deprecated filters: leaf_paths, recurse_down

tests/jq.test

@@ -952,10 +952,6 @@ path(.a[path(.b)[0]])
 [1,[[],{"a":2}]]
 [[0],[1],[1,0],[1,1],[1,1,"a"]]
 
-[leaf_paths]
-[1,[[],{"a":2}]]
-[[0],[1,1,"a"]]
-
 ["foo",1] as $p | getpath($p), setpath($p; 20), delpaths([$p])
 {"bar": 42, "foo": ["a", "b", "c", "d"]}
 "b"