[MM-55294] Migrate jest v26 to v29 to speed up "web app CI PR / test" (#25192)

webapp/platform/client/jest.config.js

@@ -7,5 +7,5 @@ module.exports = {
     moduleNameMapper: {
         '^@mattermost/types/(.*)$': '<rootDir>/../types/src/$1',
     },
-    setupFiles: ['<rootDir>/src/setupTests.ts'],
+    setupFiles: ['<rootDir>/setup_jest.ts'],
 };