## Is your feature request related to a problem?

We manage around 20 3rd party tools that our internal users can log into using G Suite (part of your enterprise / scale offering). When a user leaves, we need to disable their account. Currently we need to do this in G Suite and then any of the 3rd party tools where password login is still possible.

## Describe the solution you'd like

When a user leaves, we disable their account in G Suite and their account in PostHog becomes disabled too. Essentially, the ability to restrict specific users in PostHog to only be able to login via SSO (defaulting to this setting).

## Describe alternatives you've considered

Manually removing their account, and being the enemy of our IT manager.

## Additional context



#### *Thank you* for your feature request – we love each and every one!

posthog/api/test/test_signup.py
invite: OrganizationInvite = OrganizationInvite.objects.create(
            target_email="test+19@posthog.com", organization=self.organization,
        )
        response = self.client.get(f"/api/signup/{invite.id}/")
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertEqual(
            response.json(),
            {
                "id": str(invite.id),
                "target_email": "t*****9@posthog.com",
                "first_name": "",
                "organization_name": self.CONFIG_ORGANIZATION_NAME,
            },
        )
    def test_api_invite_sign_up_with_first_name_prevalidate(self):
        invite: OrganizationInvite = OrganizationInvite.objects.create(
            target_email="test+58@posthog.com", organization=self.organization, first_name="Jane"
        )
        response = self.client.get(f"/api/signup/{invite.id}/")
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertEqual(
            response.json(),
            {
                "id": str(invite.id),
                "target_email": "t*****8@posthog.com",
                "first_name": "Jane",
                "organization_name": self.CONFIG_ORGANIZATION_NAME,
            },
        )
    def test_api_invite_sign_up_prevalidate_for_existing_user(self):