Update internal-authentication-tutorials-access-control-consideration.rst

Remove duplicate word 'are'

Author: askmrsinh

source/includes/internal-authentication-tutorials-access-control-consideration.rst

@@ -2,7 +2,7 @@ This tutorial covers creating the minimum number of administrative
 users on the ``admin`` database *only*. For the user authentication,
 the tutorial uses the default :doc:`/core/security-scram-sha-1`
 authentication mechanism. Challenge-response security mechanisms are
-are best suited for testing or development environments. For production
+best suited for testing or development environments. For production
 environments, we recommend using :doc:`x.509
 certificates</core/security-x.509>` or :doc:`/core/security-ldap`
 (available for MongoDB Enterprise only) or :doc:`/core/kerberos`