Fix test for node info

Author: carlosdelest

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/EsqlFunctionRegistry.java

@@ -478,7 +478,7 @@ private static FunctionDefinition[][] snapshotFunctions() {
                 def(LastOverTime.class, uni(LastOverTime::new), "last_over_time"),
                 def(FirstOverTime.class, uni(FirstOverTime::new), "first_over_time"),
                 def(Term.class, bi(Term::new), "term"),
-                def(Knn.class, Knn::new, "knn"),
+                def(Knn.class, quad(Knn::new), "knn"),
                 def(StGeohash.class, StGeohash::new, "st_geohash"),
                 def(StGeohashToLong.class, StGeohashToLong::new, "st_geohash_to_long"),
                 def(StGeohashToString.class, StGeohashToString::new, "st_geohash_to_string"),
@@ -1204,4 +1204,8 @@ private static <T extends Function> TernaryBuilder<T> tri(TernaryBuilder<T> func
         return function;
     }
 
+    private static <T extends Function> QuaternaryBuilder<T> quad(QuaternaryBuilder<T> function) {
+        return function;
+    }
+
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/vector/Knn.java

@@ -146,7 +146,7 @@ public Knn(
         this(source, field, query, k, options, null, List.of());
     }
 
-    private Knn(
+    public Knn(
         Source source,
         Expression field,
         Expression query,