Modernize to hubot 14 (ESM)

- hubot 14.1.0; @hubot-friends/hubot-irc ^2.0.2; hubot-redis-brain 3.0.1
  (exact pin); hubot-help ^2.1.5; hubot-remotestorage-logger (git branch)
- drop hubot-irc, coffee-script, request, hubot-web-push-notifications, and the
  unused hubot-xmpp / hubot-incoming-webhook / hubot-auth / cheerio (they drag
  in node-xmpp-client, request and coffee-script)
- scripts/health.js -> ESM; delete scripts/example.coffee
- external-scripts.json: hubot-help, hubot-redis-brain,
  hubot-remotestorage-logger
- Procfile / run.sh: -a @hubot-friends/hubot-irc

The hubot-remotestorage-logger dep points at the feature/hubot-14 branch until
67P/hubot-remotestorage-logger#5 is merged and v2.0.0 is tagged on master.

run.sh

@@ -18,7 +18,4 @@ RS_LOGGER_USER="kosmos@5apps.com" \
 RS_LOGGER_TOKEN="change-me" \
 RS_LOGGER_PUBLIC="true" \
 WEBHOOK_TOKEN="kosmosplusplus" \
-VAPID_SUBJECT="https://example.com" \
-VAPID_PUBLIC_KEY="" \
-VAPID_PRIVATE_KEY="" \
-bin/hubot -a irc --name botka_dev
+bin/hubot -a @hubot-friends/hubot-irc --name botka_dev