Revert "Run LHCI diagnostics"

Diagnostics are already run with `lhci autorun`.

This reverts commit 8308d9d.

Author: sumanthratna

.github/workflows/lighthouse-ci.yml

@@ -34,5 +34,4 @@ jobs:
       - name: Run Lighthouse CI
         run: |
           npm install -g @lhci/cli@0.6.1
-          lhci healthcheck
           lhci autorun