[MINOR][CORE][TESTS] Fix typo in MasterDecommissionSuite class name

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

Fix a typo: `s/MasterDecommisionSuite/MasterDecommissionSuite` and `s/decommision/decommission`

### Why are the changes needed?

Typo in class name and test name.

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

No.

### How was this patch tested?

Existing tests and recompiled.

### Was this patch authored or co-authored using generative AI tooling?

No

Closes #52249 from ignitz/patch-1.

Authored-by: Yuri Niitsuma <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: ignitz

…ploy/master/MasterDecommisionSuite.scala …loy/master/MasterDecommissionSuite.scalacore/src/test/scala/org/apache/spark/deploy/master/MasterDecommisionSuite.scala renamed to core/src/test/scala/org/apache/spark/deploy/master/MasterDecommissionSuite.scala core/src/test/scala/org/apache/spark/deploy/master/MasterDecommisionSuite.scala renamed to core/src/test/scala/org/apache/spark/deploy/master/MasterDecommissionSuite.scala

@@ -27,8 +27,8 @@ import org.apache.spark.internal.config.DECOMMISSION_ENABLED
 import org.apache.spark.internal.config.UI._
 import org.apache.spark.util.Utils
 
-class MasterDecommisionSuite extends MasterSuiteBase {
-  test("SPARK-46888: master should reject worker kill request if decommision is disabled") {
+class MasterDecommissionSuite extends MasterSuiteBase {
+  test("SPARK-46888: master should reject worker kill request if decommission is disabled") {
     implicit val formats = org.json4s.DefaultFormats
     val conf = new SparkConf()
       .set(DECOMMISSION_ENABLED, false)