[SPARK-52052][CORE][FOLLOW-UP] Remove extra broadcast

### What changes were proposed in this pull request?
Remove an extra broadcast added in apache#50844

### Why are the changes needed?
Return value of broadcast is not used, so it seems it is not needed

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

### How was this patch tested?
Existing tests

### Was this patch authored or co-authored using generative AI tooling?
No

Closes apache#50874 from szehon-ho/SPARK-52052-follow.

Authored-by: Szehon Ho <[email protected]>
Signed-off-by: Hyukjin Kwon <[email protected]>

Author: szehon-ho

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JsonFileFormat.scala

@@ -96,7 +96,6 @@ case class JsonFileFormat() extends TextBasedFileFormat with DataSourceRegister
       hadoopConf: Configuration): PartitionedFile => Iterator[InternalRow] = {
     val broadcastedHadoopConf =
       SerializableConfiguration.broadcast(sparkSession.sparkContext, hadoopConf)
-      sparkSession.sparkContext.broadcast(new SerializableConfiguration(hadoopConf))
 
     val parsedOptions = new JSONOptionsInRead(
       options,