Use consistent nullish check for array.

sortedUniqBy.js

@@ -15,7 +15,7 @@ import baseSortedUniq from './.internal/baseSortedUniq.js'
  * // => [1.1, 2.3]
  */
 function sortedUniqBy(array, iteratee) {
-  return (array && array.length)
+  return (array != null && array.length)
     ? baseSortedUniq(array, iteratee)
     : []
 }