Upgrade webpack and related dependencies (#31638)

GitOrigin-RevId: e188a6ab9f7a024c1769a85e1d4e40ccb5d02213

package.json

@@ -96,7 +96,6 @@
     "lodash": "4.18.1",
     "express-session": "1.17.2",
     "ioredis": "4.27.11",
-    "webpack": "5.98.0",
     "knip": "5.64.1",
     "eslint-plugin-testing-library": "7.5.3",
     "chart.js": "4.0.1",
@@ -124,19 +123,12 @@
     "@babel/core": "7.28.5",
     "@babel/preset-env": "7.28.5",
     "@babel/register": "7.28.3",
-    "@testing-library/react": "16.3.0",
     "@vitejs/plugin-react": "4.4.1",
-    "babel-loader": "10.0.0",
-    "css-loader": "6.8.1",
     "cssnano": "7.1.4",
     "mini-css-extract-plugin": "2.7.6",
     "nodemon": "3.0.1",
     "postcss": "8.5.8",
-    "postcss-loader": "7.3.3",
     "postcss-reporter": "7.0.5",
-    "style-loader": "3.3.3",
-    "webpack-hot-middleware": "2.25.3",
-    "webpack-manifest-plugin": "5.0.0",
     "zod": "4.1.11",
     "zod-validation-error": "4.0.1",
     "simple-oauth2": "5.0.0",
@@ -185,8 +177,6 @@
     "eventsource-client": "1.1.4",
     "fake-indexeddb": "6.0.0",
     "formik": "2.2.9",
-    "handlebars": "4.7.8",
-    "html-webpack-plugin": "5.5.3",
     "katex": "0.16.28",
     "match-sorter": "6.3.1",
     "micromark": "4.0.0",
@@ -200,12 +190,9 @@
     "storybook": "10.3.5",
     "streamdown": "2.2.0",
     "tailwindcss": "3.4.17",
-    "terser-webpack-plugin": "5.3.17",
     "thread-loader": "patch:thread-loader@npm%3A4.0.2#~/.yarn/patches/thread-loader-npm-4.0.2-dab5735f54.patch",
-    "ts-loader": "9.5.4",
     "unist-util-visit": "5.0.0",
     "use-stick-to-bottom": "1.1.1",
-    "webpack-dev-server": "5.2.2",
     "zustand": "5.0.8",
     "retry-request@npm:^8.0.0": "patch:retry-request@npm%3A8.0.2#~/.yarn/patches/retry-request-npm-8.0.2-448ad084c8.patch",
     "retry-request@npm:^7.0.0": "patch:retry-request@npm%3A7.0.2#~/.yarn/patches/retry-request-npm-7.0.2-a41087680c.patch",