Remove deprecated url parameters `_source_include` and `_source_exclude` (#35097)

Removes `_source_include` and `_source_exclude` url parameters. 
These parameters have been deprecated in #33475.

Closes #22792

docs/reference/migration/migrate_7_0/api.asciidoc

@@ -102,3 +102,8 @@ status 200 - OK is now returned instead at all times.
 The Put User API response was changed in 6.5.0 to add the `created` field
 outside of the user object where it previously had been. In 7.0.0 the user
 object has been removed in favor of the top level `created` field.
+
+[float]
+==== Source filtering url parameters `_source_include` and `_source_exclude` have been removed
+
+The deprecated in 6.x url parameters are now removed. Use `_source_includes` and `_source_excludes` instead.

rest-api-spec/src/main/resources/rest-api-spec/test/get/70_source_filtering.yml

@@ -70,37 +70,3 @@
   - match:   { _id:      "1"       }
   - match:   { fields.count:  [1] }
   - match:   { _source.include.field1: v1 }
-
----
-"Deprecated _source_include and _source_exclude":
-
-  - skip:
-      version: " - 6.5.99"
-      reason: _source_include and _source_exclude are deprecated from 6.6.0
-      features: "warnings"
-
-  - do:
-      indices.create:
-        index: test_1
-        body:
-          mappings:
-            _doc:
-              properties:
-                count:
-                  type: integer
-                  store: true
-
-  - do:
-      index:
-        index:  test_1
-        type:   _doc
-        id:     1
-        body:   { "include": { "field1": "v1", "field2": "v2" }, "count": 1 }
-  - do:
-      get: { index:  test_1, type: _doc, id: 1, _source_include: include.field1 }
-      warnings:
-           - "Deprecated parameter [_source_include] used, expected [_source_includes] instead"
-  - do:
-      get: { index:  test_1, type: _doc, id: 1, _source_includes: include, _source_exclude: "*.field2" }
-      warnings:
-           - "Deprecated parameter [_source_exclude] used, expected [_source_excludes] instead"

server/src/main/java/org/elasticsearch/search/fetch/subphase/FetchSourceContext.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.search.fetch.subphase;
 
-import org.apache.logging.log4j.LogManager;
 import org.elasticsearch.common.Booleans;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
@@ -27,7 +26,6 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -46,8 +44,6 @@ import java.util.function.Function;
  */
 public class FetchSourceContext implements Writeable, ToXContentObject {
 
-    private static final DeprecationLogger DEPRECATION_LOGGER = new DeprecationLogger(LogManager.getLogger(FetchSourceContext.class));
-
     public static final ParseField INCLUDES_FIELD = new ParseField("includes", "include");
     public static final ParseField EXCLUDES_FIELD = new ParseField("excludes", "exclude");
 
@@ -110,21 +106,11 @@ public class FetchSourceContext implements Writeable, ToXContentObject {
         }
 
         String sIncludes = request.param("_source_includes");
-        String sInclude = request.param("_source_include");
-        if (sInclude != null) {
-            DEPRECATION_LOGGER.deprecated("Deprecated parameter [_source_include] used, expected [_source_includes] instead");
-            sIncludes = sInclude;
-        }
         if (sIncludes != null) {
             sourceIncludes = Strings.splitStringByCommaToArray(sIncludes);
         }
 
         String sExcludes = request.param("_source_excludes");
-        String sExclude = request.param("_source_exclude");
-        if (sExclude != null) {
-            DEPRECATION_LOGGER.deprecated("Deprecated parameter [_source_exclude] used, expected [_source_excludes] instead");
-            sExcludes = sExclude;
-        }
         if (sExcludes != null) {
             sourceExcludes = Strings.splitStringByCommaToArray(sExcludes);
         }