upgrade spotless to 7.2.1

[derrickaw]

1. First commit covers changes needed to upgrade spotless to 7.2.1 from 5.6.1 and build files. 8+ can be upgraded in another PR when many java workflows support Java 17.
2. Second commit covers the spotlessApply changes.

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[github-actions]

Assigning reviewers:

R: @ahmedabu98 for label java.
R: @liferoad for label build.
R: @sjvanrossum for label kafka.
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