remove support for _doc in derived fields

Signed-off-by: Rishabh Maurya <[email protected]>

server/src/main/java/org/opensearch/script/DerivedFieldScript.java

@@ -6,29 +6,6 @@
  * compatible open source license.
  */
 
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-/*
- * Modifications Copyright OpenSearch Contributors. See
- * GitHub history for details.
- */
-
 package org.opensearch.script;
 
 import org.apache.lucene.index.LeafReaderContext;
@@ -55,14 +32,12 @@ public abstract class DerivedFieldScript {
     public static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("derived_field", Factory.class);
     private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(DynamicMap.class);
 
-    private static final Map<String, Function<Object, Object>> PARAMS_FUNCTIONS = Map.of("doc", value -> value, "_doc", value -> {
-        deprecationLogger.deprecate(
-            "derived-field__doc",
-            "Accessing variable [doc] via [params._doc] from within an derived-field-script-context "
-                + "is deprecated in favor of directly accessing [doc]."
-        );
-        return value;
-    }, "_source", value -> ((SourceLookup) value).loadSourceIfNeeded());
+    private static final Map<String, Function<Object, Object>> PARAMS_FUNCTIONS = Map.of(
+        "doc",
+        value -> value,
+        "_source",
+        value -> ((SourceLookup) value).loadSourceIfNeeded()
+    );
 
     /**
      * The generic runtime parameters for the script.