Fix Request Insights subscription initialization (#95794)
## Summary
Pass the configured Request Insights state into the dev bundler service
so it subscribes to insight updates during initialization. The service
is constructed outside request-local tracing state, so checking only
`isRequestInsightsEnabled()` can incorrectly skip the subscription even
when Request Insights is enabled in configuration.
## Verification
- `pnpm build-all`
- `pnpm prettier --with-node-modules --ignore-path .prettierignore
--write packages/next/src/server/lib/dev-bundler-service.ts
packages/next/src/server/lib/router-server.ts`
- `npx eslint --config eslint.config.mjs --fix
packages/next/src/server/lib/dev-bundler-service.ts
packages/next/src/server/lib/router-server.ts`
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