Fix Null predicates after cherry-pick

Author: craigtaverner

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/predicate/nulls/IsNotNull.java

@@ -19,7 +19,6 @@
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
-import org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.Param;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/predicate/nulls/IsNull.java

@@ -8,11 +8,6 @@
 
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.compute.data.Block;
-import org.elasticsearch.compute.data.Page;
-import org.elasticsearch.compute.operator.DriverContext;
-import org.elasticsearch.compute.operator.EvalOperator;
-import org.elasticsearch.core.Releasables;
 import org.elasticsearch.xpack.esql.capabilities.TranslationAware;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.expression.FoldContext;
@@ -25,7 +20,6 @@
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
-import org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.Param;
@@ -34,7 +28,7 @@
 
 import java.io.IOException;
 
-public class IsNull extends UnaryScalarFunction implements EvaluatorMapper, Negatable<UnaryScalarFunction>, TranslationAware {
+public class IsNull extends UnaryScalarFunction implements Negatable<UnaryScalarFunction>, TranslationAware {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "IsNull", IsNull::new);
 
     @FunctionInfo(