fix: Skip payload class validation when merge mode is not custom

[linliu-code]

Describe the issue this Pull Request addresses

When the payload class configured during the write is different from the one from table config, the payload class validation fails the write.
When merge mode is either event_time or commit_time based, the merge behavior is not impacted by the payload class configured. Therefore, we can relax the validation constraints to ignore the payload class configuration when the merge mode is not custom.

Summary and Changelog

When the table version is >= 9, and the merge mode is not custom, we skip the payload class validation.

Tests

Unit tests for the logic change
Manual test:

1. Using Hudi 0.14.0, generated a table and populated with OverwriteWithLatestPayload class
2. Validated the table configurations to confirm the payload class.
3. Using Hudi master branch, populated more data with different payload class. No error thrown.

Impact

Better user experience.

Risk Level

None.

Documentation Update

Contributor's checklist

• Read through contributor's guide
• Enough context is provided in the sections above
• Adequate tests were added if applicable

[nsivabalan]

2 minor comments.

[hudi-bot]

CI report:

• 1802b43 Azure: SUCCESS

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build

[nsivabalan]

github action is failing due to unrelated failure. going ahead w/ landing.