Remove unused API filters

Change-Id: I4279e68947c00fda8d04b2a1cda0d50f9bfe90aa
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.ui/+/182749
Tested-by: Noopur Gupta <noopur_gupta@in.ibm.com>
Reviewed-by: Noopur Gupta <noopur_gupta@in.ibm.com>
diff --git a/org.eclipse.jdt.core.manipulation/.settings/.api_filters b/org.eclipse.jdt.core.manipulation/.settings/.api_filters
index 4a3be0c..bae7ae8 100644
--- a/org.eclipse.jdt.core.manipulation/.settings/.api_filters
+++ b/org.eclipse.jdt.core.manipulation/.settings/.api_filters
@@ -8,20 +8,4 @@
             </message_arguments>
         </filter>
     </resource>
-    <resource path="core extension/org/eclipse/jdt/internal/corext/dom/ASTFlattener.java" type="org.eclipse.jdt.internal.corext.dom.ASTFlattener">
-        <filter comment="This is a Java 16 preview feature" id="640712815">
-            <message_arguments>
-                <message_argument value="PatternInstanceofExpression"/>
-                <message_argument value="ASTFlattener"/>
-                <message_argument value="getLeftOperand()"/>
-            </message_arguments>
-        </filter>
-        <filter comment="This is a Java 16 preview feature" id="640712815">
-            <message_arguments>
-                <message_argument value="PatternInstanceofExpression"/>
-                <message_argument value="ASTFlattener"/>
-                <message_argument value="getRightOperand()"/>
-            </message_arguments>
-        </filter>
-    </resource>
 </component>