build: move from pnpm to npm

Replace pnpm-lock.yaml with package-lock.json. The three overrides move to
package.json#overrides, including the request -> @cypress/request alias, which
npm supports as an override value. allowBuilds for es5-ext becomes
package.json#allowScripts. The Dockerfile installs with npm ci instead of
enabling corepack.

package.json

@@ -2,7 +2,6 @@
   "name": "store-scraper",
   "type": "module",
   "version": "1.0.0",
-  "packageManager": "pnpm@11.1.1",
   "description": "Host [google-play-scraper](https://github.com/facundoolano/google-play-scraper) and [app-store-scraper](https://github.com/facundoolano/app-store-scraper)",
   "main": "index.js",
   "scripts": {
@@ -25,5 +24,13 @@
     "app-store-scraper": "^0.18.0",
     "express": "^5.2.0",
     "google-play-scraper": "^10.1.3"
+  },
+  "overrides": {
+    "qs": "^6.15.3",
+    "request": "npm:@cypress/request@^4.0.1",
+    "undici": "7.28.0"
+  },
+  "allowScripts": {
+    "es5-ext": true
   }
 }