Avoid rate limit error on scheduled daily test (#376)

* Avoid rate limit error on scheduled daily test

There appears to be an issue when scanning issues for a matching issue
title which triggers a secondary rate limit error. As this is not the
primary feature we are using and an optimization, removing this for now

See: https://github.com/mlcommons/newhelm/actions/runs/8604877224/job/23579923706
See: JasonEtco/create-an-issue#142

.github/workflows/scheduled-tests.yml

@@ -90,4 +90,3 @@ jobs:
         RUN_ID: ${{ github.run_id }}
       with:
         filename: .github/failed-scheduled-issue.md
-        update_existing: true