[SPARK-34004][SQL] Change FrameLessOffsetWindowFunction as sealed abstract class

[beliefer]

What changes were proposed in this pull request?

Change FrameLessOffsetWindowFunction as sealed abstract class so that simplify pattern match.

Why are the changes needed?

Simplify pattern match

Does this PR introduce any user-facing change?

Yes

How was this patch tested?

Jenkins test

[HyukjinKwon]

@beliefer just out of curiosity, I think your master branch in your fork is not synced properly for whatever reason. When you sync your master branch, you should rebase instead of merge. Otherwise, the merge commits show as shown in this PR above. I think you will have to git rebase --force for your master branch to get rid of the merge commits above.

[SparkQA]

Kubernetes integration test starting
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/38248/

[SparkQA]

Kubernetes integration test status success
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/38248/

[SparkQA]

Test build #133660 has finished for PR 31026 at commit bebe4c2.

• This patch fails PySpark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[beliefer]

retest this please

[SparkQA]

Test build #133686 has finished for PR 31026 at commit bebe4c2.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[beliefer]

retest this please

[SparkQA]

Kubernetes integration test starting
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/38291/

[SparkQA]

Kubernetes integration test status success
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/38291/

[dongjoon-hyun]

+1, LGTM. Thank you, @beliefer and @HyukjinKwon .
Merged to master for Apache Spark 3.2.0.

[beliefer]

@dongjoon-hyun Thanks for your help! @HyukjinKwon Thanks for your sincerely suggestion, I will learn and try it.

[HyukjinKwon]

LGTM too

[SparkQA]

Test build #133703 has finished for PR 31026 at commit bebe4c2.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.