api: Delete ancient generate_204 endpoint.

This endpoint was needed by the ancient pre-electron desktop app
written in QT; we removed support for that in practice a long time
ago, and even the custom error messages for it in
5a22e73cc6.

So we can delete this endpoint as well.

zerver/tests/test_home.py

@@ -867,11 +867,6 @@ class HomeTest(ZulipTestCase):
             compute_navbar_logo_url(page_params), "/static/images/logo/zulip-org-logo.svg?version=0"
         )
 
-    def test_generate_204(self) -> None:
-        self.login("hamlet")
-        result = self.client_get("/api/v1/generate_204")
-        self.assertEqual(result.status_code, 204)
-
     def test_furthest_read_time(self) -> None:
         msg_id = self.send_test_message("hello!", sender_name="iago")
 

zerver/tests/test_openapi.py

@@ -288,8 +288,6 @@ class OpenAPIArgumentsTest(ZulipTestCase):
         "/realm/deactivate",
         "/realm/subdomain/{subdomain}",
         #### Other low value endpoints
-        # Used for dead desktop app to test connectivity.  To delete.
-        "/generate_204",
         # Used for failed approach with dead Android app.
         "/fetch_google_client_id",
         # API for video calls we're planning to remove/replace.

zerver/views/registration.py

@@ -663,10 +663,6 @@ def accounts_home_from_multiuse_invite(request: HttpRequest, confirmation_key: s
     )
 
 
-def generate_204(request: HttpRequest) -> HttpResponse:
-    return HttpResponse(content=None, status=204)
-
-
 def find_account(request: HttpRequest) -> HttpResponse:
     from zerver.context_processors import common_context
 

zproject/urls.py

@@ -129,7 +129,6 @@ from zerver.views.registration import (
     check_prereg_key_and_redirect,
     create_realm,
     find_account,
-    generate_204,
     realm_redirect,
 )
 from zerver.views.report import (
@@ -248,8 +247,6 @@ if settings.TWO_FACTOR_AUTHENTICATION_ENABLED:
 v1_api_and_json_patterns = [
     # realm-level calls
     rest_path("realm", PATCH=update_realm),
-    # Returns a 204, used by desktop app to verify connectivity status
-    path("generate_204", generate_204),
     path("realm/subdomain/<subdomain>", check_subdomain_available),
     # realm/domains -> zerver.views.realm_domains
     rest_path("realm/domains", GET=list_realm_domains, POST=create_realm_domain),