chore(sentry/nextjs): webpack as optional peer-dependency (#4634)

- fix a warning about a missing peer-dep on webpack.
- should fix install with yarn pnp / pnpm modules linkers

Author: belgattitude

packages/nextjs/package.json

@@ -37,6 +37,11 @@
     "react": "15.x || 16.x || 17.x",
     "webpack": ">= 4.0.0"
   },
+  "peerDependenciesMeta": {
+    "webpack": {
+      "optional": true
+    }
+  },
   "scripts": {
     "build": "run-p build:cjs build:esm",
     "build:cjs": "tsc -p tsconfig.cjs.json",