chore(login): update the login banners (#59186)

Updated the CTA from Register now to Learn more for the Launch Week
banner.

src/sentry/templates/sentry/partial/alerts.html

@@ -78,9 +78,9 @@
   <div class="alert-banner">
     <div class="alert-message">
       {% if banner_choice == 0 %}
-      Discover all our latest product releases at Sentry Launch Week coming Nov 13-17. &nbsp<a target="_blank" href="https://sentry.io/events/launch-week/?utm_medium=banner&utm_source=sentry-app&utm_campaign=login-launch-week&utm_content=login-banner&utm_term=">Register now</a>.
+      Discover all our latest product releases at Sentry Launch Week coming Nov 13-17. &nbsp<a target="_blank" href="https://sentry.io/events/launch-week/?utm_medium=banner&utm_source=sentry-app&utm_campaign=login-launch-week&utm_content=login-banner&utm_term=">Learn more</a>.
       {% elif banner_choice == 1 %}
-      Discover all our latest product releases at Sentry Launch Week coming Nov 13-17. &nbsp<a target="_blank" href="https://sentry.io/events/launch-week/?utm_medium=banner&utm_source=sentry-app&utm_campaign=login-launch-week&utm_content=login-banner&utm_term=">Register now</a>.
+      Discover all our latest product releases at Sentry Launch Week coming Nov 13-17. &nbsp<a target="_blank" href="https://sentry.io/events/launch-week/?utm_medium=banner&utm_source=sentry-app&utm_campaign=login-launch-week&utm_content=login-banner&utm_term=">Tune in</a>.
       {% endif %}
     </div>
   </div>