ci: drop ignore for old helm-pr-prerelease.yml (deleted in this PR)

Author: nicktrn

.github/workflows/pr_checks.yml

@@ -8,7 +8,6 @@ on:
       - ".changeset/**"
       - "hosting/**"
       - ".github/workflows/helm-prerelease.yml"
-      - ".github/workflows/helm-pr-prerelease.yml"
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}