comparisons should be made on the value channel only

The interlacer rule is "operations are applied to the value channel"
and missing values are automatically masked out. the original
behavior did not follow this in order to allow for comparsion
of missing reasons. Instead, for missing reason comparsions
we will need to define new equality operators that compare
both values and missing reason channels.

See discussion here for more info: r-lib/vctrs#1928

R/interlaced.R

@@ -411,7 +411,7 @@ vec_restore.interlacer_interlaced <- function(x, to, ...) {
 
 #' @export
 vec_proxy_equal.interlacer_interlaced <- function(x, ...) {
-  if_else(is.empty(x), list(NULL), vec_chop(x))
+  value_channel(x)
 }
 
 #' @export