Airflow 2.1.0, Docker

**What happened**:

Users with the Guest role assigned are stuck in a redirect loop once they attempt to login successfully to the web interface.

**What you expected to happen**:

Get minimal access to the dashboard with the appropriate views for a guest role

**How to reproduce it**:
1. Assign a guest role to any user and remove any other roles with the administrator user.
2. Logout from the admin account 
3. Login as the guest user
4. You will notice constant HTTP redirects, and the dashboard will not show up.


airflow/www/security.py
"""
        Verify whether a given user could perform a certain action
        (e.g can_read, can_write) on the given resource.
        :param action_name: action_name on resource (e.g can_read, can_edit).
        :type action_name: str
        :param resource_name: name of view-menu or resource.
        :type resource_name: str
        :param user: user name
        :type user: str
        :return: Whether user could perform certain action on the resource.
        :rtype bool
        """
        if not user:
            user = g.user
        if user.is_anonymous:
            user.roles = self.get_user_roles(user)
        has_access = self._has_access(user, action_name, resource_name)
        
        if self.is_dag_resource(resource_name):
            if action_name == permissions.ACTION_CAN_READ:
                has_access |= self.can_read_dag(resource_name, user)
            elif action_name == permissions.ACTION_CAN_EDIT:
                has_access |= self.can_edit_dag(resource_name, user)
        return has_access
    def _has_access(self, user: User, action_name: str, resource_name: str) -> bool: