refactor(qcommon): minor java21 refactoring as advised by IDEA

[holmeso]

Description

Minor changes to use some Java 21 features, formatting, etc.

How Has This Been Tested?

Unit tests pass

Are WDL Updates Required?

no

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[holmesoA]

too many changes to review, so am going to rely on the unit tests informing me of any breaking changes