fix: Don't do cgaz updates on modes that aren't defrag

[jason-e]

I recently fixed some ConVar access debugging stuff and saw that cgaz's onUpdate is always running, even when not on the Defrag gamemode. Let me know if there's a more correct way to fix this.

Checks

• I have thoroughly tested all of the code I have modified/added/removed to ensure something else did not break
• I have followed semantic commit messages e.g. feat: Add foo, chore: Update bar, etc...
• My branch has a clear history of changes that can be easy to follow when being reviewed commit-by-commit
• My branch is functionally complete; the only changes to be done will be those potentially requested in code review
• All changes requested in review have been fixuped into my original commits.
• Fully tokenized all my strings (no hardcoded English strings!!) and supplied bulk JSON strings below

[PeenScreeker]

LGTM, thanks for Handling this