Chore: remove lefthook.rc (#103713)

Author: ryantxu

.github/CODEOWNERS

@@ -461,7 +461,6 @@
 /stylelint.config.js @grafana/frontend-ops
 /tools/ @grafana/frontend-ops
 /lefthook.yml @grafana/frontend-ops
-/lefthook.rc @grafana/frontend-ops
 /.husky/pre-commit @grafana/frontend-ops
 /cypress.config.js @grafana/grafana-frontend-platform
 /.levignore.js @grafana/plugins-platform-frontend