Fix version check in yml test for the bug fix of constant_keyword field type not working (opensearch-project#15019)

Signed-off-by: Gao Binlong <gbinlong@amazon.com>

Author: gaobinlong

rest-api-spec/src/main/resources/rest-api-spec/test/index/110_constant_keyword.yml

@@ -8,8 +8,8 @@
 
 "Mappings and Supported queries":
   - skip:
-      version: " - 2.99.99"
-      reason: "fixed in 3.0.0"
+      version: " - 2.15.99"
+      reason: "fixed in 2.16.0"
 
   # Create index with constant_keyword field type
   - do: