ref(cells): Remove the legacy org invite route

this removes the pre-silo organization invite path.

this fundamentally does not work in the regional or cell world
-- all org specific routes need to contain the org identifier
(id or slug) in order to target the correct cell.

since we have not sent invites using this path for many years, it
should be safe to remove

this is a prequisite to #112053
and other codebase cleanups

Author: lynnagara

src/sentry/api/urls.py

@@ -3791,11 +3791,6 @@ def create_group_urls(name_prefix: str) -> list[URLPattern | URLResolver]:
         DataExportNotificationsEndpoint.as_view(),
         name="sentry-api-0-data-export-notifications",
     ),
-    re_path(
-        r"^accept-invite/(?P<member_id>[^/]+)/(?P<token>[^/]+)/$",
-        AcceptOrganizationInvite.as_view(),
-        name="sentry-api-0-accept-organization-invite",
-    ),
     re_path(
         r"^notification-defaults/$",
         NotificationDefaultsEndpoints.as_view(),