fix(gh): update command to run tests

Author: Rotzbua

.github/PULL_REQUEST_TEMPLATE.md

@@ -30,5 +30,5 @@ the [forum](https://discourse.nodered.org) or
 
 - [ ] I have read the [contribution guidelines](https://github.com/node-red/node-red/blob/master/CONTRIBUTING.md)
 - [ ] For non-bugfix PRs, I have discussed this change on the forum/slack team.
-- [ ] I have run `grunt` to verify the unit tests pass
+- [ ] I have run `npm run test` to verify the unit tests pass
 - [ ] I have added suitable unit tests to cover the new/changed functionality