Update Likely Subtags for UTS 35

Cherry-picked from BZ 1927706 Part 6.

js/src/builtin/intl/make_intl_data.py

@@ -1235,10 +1235,9 @@ def writeCLDRLanguageTagLikelySubtagsTest(println, data, url):
 
         # Step 2: Lookup.
         searches = ((language, script, region),
++                   (language, script, None),
                     (language, None, region),
-                    (language, script, None),
-                    (language, None, None),
-                    ("und", script, None))
+                    (language, None, None))
         search = next(search for search in searches if search in likely_subtags)
 
         (language_s, script_s, region_s) = search