Use randomScore instead of randomReproducible

With this commit we align our benchmarks with
elastic/elasticsearch#40186 which has removed the function
`randomReproducible` and added a new function `randomScore`.

Relates elastic/elasticsearch#40186

geonames/operations/default.json

@@ -273,7 +273,7 @@
               "match_all": {}
             },
             "script": {
-              "source": "randomReproducible(Long.toString(doc['_seq_no'].value), 100)"
+              "source": "randomScore(100, '_seq_no')"
             }
           }
         }
@@ -293,4 +293,4 @@
       "name": "large_prohibited_terms",
       "operation-type": "search",
       "param-source": "prohibited-terms-query-source"
-    }
+    }