[SPARK-44705][FOLLOWUP] Fix Deprecation Version of ContetAwareIterator

### What changes were proposed in this pull request?
apache#42385 deprecated `ContextAwareIterator` but the deprecation version was incorrectly set to 3.5. This PR fixes it to be 4.0.

### Why are the changes needed?
Fix deprecation version.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
Not needed.

Closes apache#42494 from utkarsh39/SPARK-44705-fix-deprecation-version.

Authored-by: Utkarsh <utkarsh.agarwal@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>

core/src/main/scala/org/apache/spark/ContextAwareIterator.scala

@@ -33,7 +33,7 @@ import org.apache.spark.annotation.DeveloperApi
  * @deprecated since 4.0.0 as its only usage for Python evaluation is now extinct
  */
 @DeveloperApi
-@deprecated("Only usage for Python evaluation is now extinct", "3.5.0")
+@deprecated("Only usage for Python evaluation is now extinct", "4.0.0")
 class ContextAwareIterator[+T](val context: TaskContext, val delegate: Iterator[T])
   extends Iterator[T] {