Turbopack: don't use build id for pages router client-side manifests (#88641)
Goes from
```
/_next/static/THE_BUILD_ID/_buildManifest.js?dpl=123
/_next/static/THE_BUILD_ID/_ssgManifest.js?dpl=123
/_next/static/THE_BUILD_ID/_clientMiddlewareManifest.js?dpl=123
```
to
```
/_next/static/_buildManifest.js?dpl=123
/_next/static/_ssgManifest.js?dpl=123
/_next/static/_clientMiddlewareManifest.js?dpl=123
```
if skew protection is enabled. This makes the build-manifest.json not depend on the build id
Closes PACK-6535