[SPARK-54081] Add word-count-preview.yaml Example

[dongjoon-hyun]

What changes were proposed in this pull request?

This PR aims to add word-count-preview.yaml Example.

Why are the changes needed?

To provide a Spark Job shuffle example.

Does this PR introduce any user-facing change?

No behavior change because this is a new example.

How was this patch tested?

Manual review.

$ kubectl apply -f examples/word-count-preview.yaml

$ kubectl logs -f word-count-0-driver
...
25/10/29 23:48:04 INFO DAGScheduler: Job 0 finished: collect at JavaWordCount.java:53, took 3544.885793 ms
-Psparkr: 1
-B: 1
Spark: 1
-Pkubernetes: 1
-Pyarn: 1
revision: 1
Build: 1
built: 1
c5ff48cc2b2): 1
(git: 1
-Phadoop-3: 1
4.1.0-preview2: 1
flags:: 1
-Phive-thriftserver: 1
for: 1
-Phive: 1
3.4.2: 1
Hadoop: 1

$ k get sparkapp
NAME         CURRENT STATE      AGE
word-count   ResourceReleased   2m35s

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

No.

[viirya]

To provide a Spark Job shuffle example.

Is this shuffle example?

[dongjoon-hyun]

Thank you, @viirya . Yes,

[dongjoon-hyun]

Merged to main.

[peter-toth]

Late LGTM.