fix: address a minor issue that might cause duplicate entries in cluster decisions (status)

[michaelawyu]

Description of your changes

This PR fixes a minor issue where duplicate entries might occur in cluster decisions when a cluster is picked and then unpicked without having a scheduling policy change.

I have:

• [x] Run make reviewable to ensure this PR is ready for review.

How has this code been tested

• [x] Unit tests
• [x] Integration tests

Special notes for your reviewer