chore: remove uneeded pr review action (backport #18488) (#18489)

Co-authored-by: Marko <marbar3778@yahoo.com>

.github/workflows/pr-reviews.yml

@@ -1,26 +0,0 @@
-# Request review on PRs without changing our codeowners file (which is stricter than review team)
-name: Request review on PRs
-
-on:
-  pull_request_target:
-    types:
-      - opened
-      - reopened
-      - ready_for_review
-    branches:
-      - "main"
-      - "release/**"
-
-jobs:
-  request:
-    permissions:
-      pull-requests: write
-    name: Request reviews on opened PRs
-    runs-on: ubuntu-latest
-    steps:
-      - name: Create PR review request
-        if: ${{ !github.event.pull_request.draft }}
-        run: gh pr edit $PR_URL --add-reviewer @cosmos/sdk-core-review
-        env:
-          GH_TOKEN: ${{ secrets.PRBOT_PAT }}
-          PR_URL: ${{ github.event.pull_request.html_url }}