The "small-pr" label doesn't update even if PR drops below or rises above threshold

[ThioJoe]

I noticed in the core repo, it seems that the "small-pr" label automatically gets applied only when the pull request is first submitted. But I think it would be best if it automatically updated depending on updates to the PR. This could increase efficiency in identifying which pull requests can be reviewed quickly.

• Example dropping below the threshold: home-assistant/core#91763 (My own PR. Goes from 70 additions to 24)

• Example rising above the threshold: home-assistant/core#91943 (Goes from 25 additions to 57)