Merge pull request #27078 from backstage/rugvip/cleanup

cli: remove legacy backend start

packages/cli/package.json

@@ -141,7 +141,6 @@
     "rollup-plugin-esbuild": "^6.1.1",
     "rollup-plugin-postcss": "^4.0.0",
     "rollup-pluginutils": "^2.8.2",
-    "run-script-webpack-plugin": "^0.2.0",
     "semver": "^7.5.3",
     "style-loader": "^3.3.1",
     "sucrase": "^3.20.2",
@@ -152,7 +151,6 @@
     "util": "^0.12.3",
     "webpack": "^5.70.0",
     "webpack-dev-server": "^5.0.0",
-    "webpack-node-externals": "^3.0.0",
     "yaml": "^2.0.0",
     "yargs": "^16.2.0",
     "yml-loader": "^2.1.0",