Avoid loading route-pattern by default

[brophdawg11]

This moves the route-pattern matcher behind a separate react-router/route-pattern entry point, so applications only include @remix-run/route-pattern when they opt into future.unstable_routePatternMatching.

import { unstable_routePatternMatching } from "react-router/route-pattern";

createBrowserRouter(routes, {
  future: { unstable_routePatternMatching },
});

In a production Vite bundle, the default path decreases from 32.82 kB to 26.43 kB gzip, avoiding 6.39 kB for applications that do not opt in. Regression coverage verifies the default router entry does not load the route-pattern modules.

[github-actions]

Preview Build Available

Preview builds have been created for this PR. You can install react-router using:

pnpm install "remix-run/react-router#preview/pr-15463&path:packages/react-router"

And/or install other packages via:

pnpm install "remix-run/react-router#preview/pr-15463&path:packages/react-router-dev"
pnpm install "remix-run/react-router#preview/pr-15463&path:packages/react-router-express"
pnpm install "remix-run/react-router#preview/pr-15463&path:packages/react-router-node"
pnpm install "remix-run/react-router#preview/pr-15463&path:packages/react-router-serve"

These preview builds will be updated automatically as you push new commits.