create_user: Use silent mentions in user join notices.

This provides more information (email, etc.) when clicked on
while being better adapted to email_address_visibility existing.

Fixes #27243.

zerver/actions/create_user.py

@@ -254,7 +254,7 @@ def process_new_human_user(
                 get_system_bot(settings.NOTIFICATION_BOT, prereg_user.referred_by.realm_id),
                 prereg_user.referred_by,
                 _("{user} accepted your invitation to join Zulip!").format(
-                    user=f"{user_profile.full_name} <`{user_profile.email}`>"
+                    user=silent_mention_syntax_for_user(user_profile)
                 ),
             )
 

zerver/tests/test_invite.py

@@ -957,7 +957,7 @@ class InviteUserTest(InviteUserBase):
         self.assertEqual(inviter_msg.sender.email, "notification-bot@zulip.com")
         self.assertTrue(
             inviter_msg.content.startswith(
-                f"alice_zulip.com <`{invitee_profile.email}`> accepted your",
+                f"@_**{invitee_profile.full_name}|{invitee_profile.id}** accepted your",
             )
         )
 

zerver/tests/test_users.py

@@ -826,7 +826,7 @@ class QueryCountTest(ZulipTestCase):
 
         prereg_user = PreregistrationUser.objects.get(email="fred@zulip.com")
 
-        with self.assert_database_query_count(92):
+        with self.assert_database_query_count(93):
             with self.assert_memcached_count(23):
                 with self.capture_send_event_calls(expected_num_events=11) as events:
                     fred = do_create_user(