[7.x] remove legacy uiSettings mixin (#76255)

src/core/server/ui_settings/integration_tests/lib/servers.ts

@@ -73,9 +73,9 @@ export function getServices() {
     httpServerMock.createKibanaRequest()
   );
 
-  const uiSettings = kbnServer.server.uiSettingsServiceFactory({
-    savedObjectsClient,
-  });
+  const uiSettings = kbnServer.newPlatform.start.core.uiSettings.asScopedToClient(
+    savedObjectsClient
+  );
 
   services = {
     kbnServer,

src/legacy/server/kbn_server.d.ts

@@ -45,7 +45,6 @@ import { LegacyConfig, ILegacyService, ILegacyInternals } from '../../core/serve
 import { UiPlugins } from '../../core/server/plugins';
 import { CallClusterWithRequest, ElasticsearchPlugin } from '../core_plugins/elasticsearch';
 import { UsageCollectionSetup } from '../../plugins/usage_collection/server';
-import { UiSettingsServiceFactoryOptions } from '../../legacy/ui/ui_settings/ui_settings_service_factory';
 import { HomeServerPluginSetup } from '../../plugins/home/server';
 
 // lot of legacy code was assuming this type only had these two methods
@@ -78,7 +77,6 @@ declare module 'hapi' {
       name: string,
       factoryFn: (request: Request) => Record<string, any>
     ) => void;
-    uiSettingsServiceFactory: (options?: UiSettingsServiceFactoryOptions) => IUiSettingsClient;
     logWithMetadata: (tags: string[], message: string, meta: Record<string, any>) => void;
     newPlatform: KbnServer['newPlatform'];
   }

src/legacy/ui/ui_mixin.js

@@ -19,10 +19,8 @@
 
 import { uiAppsMixin } from './ui_apps';
 import { uiRenderMixin } from './ui_render';
-import { uiSettingsMixin } from './ui_settings';
 
 export async function uiMixin(kbnServer) {
   await kbnServer.mixin(uiAppsMixin);
-  await kbnServer.mixin(uiSettingsMixin);
   await kbnServer.mixin(uiRenderMixin);
 }

src/legacy/ui/ui_render/ui_render_mixin.js

@@ -21,6 +21,7 @@ import { createHash } from 'crypto';
 import Boom from 'boom';
 import { i18n } from '@kbn/i18n';
 import * as UiSharedDeps from '@kbn/ui-shared-deps';
+import { KibanaRequest } from '../../../core/server';
 import { AppBootstrap } from './bootstrap';
 import { getApmConfig } from '../apm';
 
@@ -79,7 +80,10 @@ export function uiRenderMixin(kbnServer, server, config) {
         auth: authEnabled ? { mode: 'try' } : false,
       },
       async handler(request, h) {
-        const uiSettings = request.getUiSettingsService();
+        const soClient = kbnServer.newPlatform.start.core.savedObjects.getScopedClient(
+          KibanaRequest.from(request)
+        );
+        const uiSettings = kbnServer.newPlatform.start.core.uiSettings.asScopedToClient(soClient);
 
         const darkMode =
           !authEnabled || request.auth.isAuthenticated