Fix error msg in CalcitePPLFunctionTypeTest

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

ppl/src/test/java/org/opensearch/sql/ppl/calcite/CalcitePPLFunctionTypeTest.java

@@ -47,8 +47,8 @@ public void testComparisonWithDifferentType() {
     verifyErrorMessageContains(
         t,
         // Temporary fix for the error message as LESS function has two variants. Will remove
-        // [IP,IP],[IP,STRING],[STRING,IP] when merging the two variants.
-        "LESS function expects {[IP,IP],[IP,STRING],[STRING,IP],[COMPARABLE_TYPE,COMPARABLE_TYPE]},"
+        // [IP,IP] when merging the two variants.
+        "LESS function expects {[IP,IP],[COMPARABLE_TYPE,COMPARABLE_TYPE]},"
             + " but got [STRING,INTEGER]");
   }