fix(next): pg-cloudflare build issue (#12242)

Fixes next build issue related to `cloudflare:sockets`.

Related Next.js discussion thread here:
vercel/next.js#50177

Commands to recreate issue locally

```sh
pnpm run script:pack --dest templates/with-postgres && \
pnpm run script:build-template-with-local-pkgs with-postgres postgresql://localhost:5432/payloadtests
```

**Build Error:**
```
Failed to compile.

cloudflare:sockets
Module build failed: UnhandledSchemeError: Reading from "cloudflare:sockets" is not handled by plugins (Unhandled scheme).
Webpack supports "data:" and "file:" URIs by default.
You may need an additional plugin to handle "cloudflare:" URIs.
    at /home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:29:408376
    at Hook.eval [as callAsync] (eval at create (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:14:9224), <anonymous>:6:1)
    at Hook.CALL_ASYNC_DELEGATE [as _callAsync] (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:14:6378)
    at Object.processResource (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:29:408301)
    at processResource (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/loader-runner/LoaderRunner.js:1:5308)
    at iteratePitchingLoaders (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/loader-runner/LoaderRunner.js:1:4667)
    at runLoaders (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/loader-runner/LoaderRunner.js:1:8590)
    at NormalModule._doBuild (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:29:408163)
    at NormalModule.build (/home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:29:410176)
    at /home/runner/work/payload/payload/templates/with-postgres/node_modules/.pnpm/next@15.3.0_react-dom@19.1.0_react@19.1.0__react@19.1.0_sass@1.77.4/node_modules/next/dist/compiled/webpack/bundle5.js:29:82494
```

Author: denolfe

packages/next/src/withPayload.js

@@ -140,6 +140,13 @@ export const withPayload = (nextConfig = {}, options = {}) => {
           { module: /node_modules\/mongodb\/lib\/bson\.js/ },
           { file: /node_modules\/mongodb\/lib\/bson\.js/ },
         ],
+        plugins: [
+          ...(incomingWebpackConfig?.plugins || []),
+          // Fix cloudflare:sockets error: https://github.com/vercel/next.js/discussions/50177
+          new webpackOptions.webpack.IgnorePlugin({
+            resourceRegExp: /^pg-native$|^cloudflare:sockets$/,
+          }),
+        ],
         resolve: {
           ...(incomingWebpackConfig?.resolve || {}),
           alias: {