Emails: remove the yarn.lock (#18724)
Emails: remove the yarn.lock (#18724)

yarn.lock with old deps triggers the github vuln errors, if you update deps
to newest versions grunt commands will stop working. Since we generating
emails here, vuln errors seems needless.

We need to remove grunt dependency anyhow
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana