text: Title: Don't run check-release on release
  Body: ## Description
  
  This is what our `check-release` workflow looks like:
  
  ```
  name: Check Release
  on:
    push:
      branches: ["*"]
    pull_request:
      branches: ["*"]
    release:
      types: [published]
    schedule:
      - cron: "0 0 * * *"
  ```
  
  The problem is that running this on release always fails, probably because the branch was updated too recently for this workflow to include the release commit. See: https://github.com/jupyterlab/jupyter-ai/actions/workflows/check-release.yml?query=is%3Afailure
  
  Running this on release is unnecessary anyways since a release always results in a commit being pushed, which triggers the `on: push` hook.
  