Fix logic for getting maintainer ids for benchmark workflow

Signed-off-by: Rishabh Singh <[email protected]>

.github/workflows/benchmark-pull-request.yml

@@ -109,7 +109,7 @@ jobs:
           echo "prHeadRefSha=$headRefSha" >> $GITHUB_ENV
       - id: get_approvers
         run: |
-          echo "approvers=$(cat .github/CODEOWNERS | grep '^\*'  | tr -d '* ' | sed 's/@/,/g' | sed 's/,//1')" >> $GITHUB_OUTPUT
+          echo "approvers=$(cat .github/CODEOWNERS | grep '^/MAINTAINERS.md' | sed 's/^\/MAINTAINERS.md @//g' | tr -d '@' | tr ' ' ',' | tr -d '\n')" >> $GITHUB_OUTPUT
       - uses: trstringer/manual-approval@v1
         if: (!contains(steps.get_approvers.outputs.approvers, github.event.comment.user.login))
         with: