Fix typo in ResourceQuota Admission Controller Comment

Created by: chansuke

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

This PR improves the clarity and correctness of documentation within the code. Specifically, it fixes a grammatical error in a comment. While this change might appear minor, accurate and clear comments are crucial for ongoing maintenance, understanding of the codebase, and easing the onboarding process for new contributors.

Which issue(s) this PR fixes:

Fixes #121427

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.: