[MINOR][SQL] Remove unnecessary extend from BroadcastHashJoinExec

### What changes were proposed in this pull request?

This is just a minor fix. `HashJoin` already extends `JoinCodegenSupport`. So we don't need `CodegenSupport` here for `BroadcastHashJoinExec`. Submitted separately as a PR here per #31802 (comment) .

### Why are the changes needed?

Clean up code.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Existing unit tests.

Closes #31805 from c21/bhj-minor.

Authored-by: Cheng Su <chengsu@fb.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>

sql/core/src/main/scala/org/apache/spark/sql/execution/joins/BroadcastHashJoinExec.scala

@@ -46,7 +46,7 @@ case class BroadcastHashJoinExec(
     left: SparkPlan,
     right: SparkPlan,
     isNullAwareAntiJoin: Boolean = false)
-  extends HashJoin with CodegenSupport {
+  extends HashJoin {
 
   if (isNullAwareAntiJoin) {
     require(leftKeys.length == 1, "leftKeys length should be 1")