chore: update rspack to 1.5.0 (#82863)
In the rspack-1.5.0 rc.0 release, many NAPI-side optimizations have been
added, reducing the build time for app router projects from 20.0s to
15.0s.
## Note
I benchmarked performance using this repo:
https://github.com/SyMind/chakra-ui-docs/tree/next-rspack to test the
Next.js app router.
I tested the performance with the following steps:
1. Execute pnpm run dev or pnpm run build
2. Wait for the server to be ready (indicated by the 'Ready' message)
3. Run curl on the root endpoint (/)
4. Each build was run 5 times, and the shortest time to reach "Compiled
successfully" was recorded.
Test environment: Apple M1 Pro CPU
