Remove bootstrap class in licensed user count

What does this MR do?

Remove bootstrap class in licensed user count

• remove alert-primary class because gl-alert-info already is appended

Screenshots

Before	After

How to reproduce

1. Checkout the branch
2. Update the code below to force the error

diff --git a/ee/app/views/layouts/header/_licensed_user_count_threshold.html.haml b/ee/app/views/layouts/header/_licensed_user_count_threshold.html.haml
index bab6239f16a..a77545c7071 100644
--- a/ee/app/views/layouts/header/_licensed_user_count_threshold.html.haml
+++ b/ee/app/views/layouts/header/_licensed_user_count_threshold.html.haml
@@ -1,4 +1,4 @@
-- return unless show_active_user_count_threshold_banner?
+- return if show_active_user_count_threshold_banner?
@@ -6,7 +6,7 @@
-      = _('Your instance has %{remaining_user_count} users remaining of the %{total_user_count} included in your subscription. You can add more users than the number included in your license, and we will include the overage in your next bill.') % { remaining_user_count: remaining_user_count, total_user_count: total_user_count }
+      = _('Your instance has %{remaining_user_count} users remaining of the %{total_user_count} included in your subscription. You can add more users than the number included in your license, and we will include the overage in your next bill.') % { remaining_user_count: 5, total_user_count: 5 }

3. Navigate to a project

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #233691 (closed) Related to gitlab-com/www-gitlab-com#8498 (closed)