Disable Rest Test for field collapsing/field alias

Disables the rest tests introduced in
    b83354e.
    Make sure that field collapsing supports field aliases. (#32648)

These tests need setup that is not compatible with older versions and
cause BWC tests to fail

Author: tvernum

rest-api-spec/src/main/resources/rest-api-spec/test/search/110_field_collapsing.yml

@@ -7,7 +7,7 @@ setup:
             test:
               properties:
                 numeric_group: { type: integer }
-                group_alias: { type: alias, path: numeric_group }
+#                group_alias: { type: alias, path: numeric_group }
 
   - do:
       index:
@@ -398,8 +398,8 @@ setup:
 ---
 "field collapsing on a field alias":
   - skip:
-      version: " - 6.3.99"
-      reason: Field aliases were introduced in 6.4.0.
+      version: " - 6.9.99"
+      reason: Field aliases require non-BWC index setup / Field aliases were introduced in 6.4.0.
   - do:
       search:
         index: test