[FLINK-40317][tests] Make DeletesByKeySemanticTests more stable

[snuyanzin]

What is the purpose of the change

The PR is to make DeletesByKeySemanticTests more stable by using testMaterializeData

Brief change log

DeletesByKeySemanticTests

Verifying this change

run same tests 10000 times locally

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): ( no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? ( no)
• If yes, how is the feature documented? (not applicable)

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: [Tool Name and Version]

[flinkbot]

CI report:

• 90b786e Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[AHeise]

LGTM.