fix: double fragment on navigation (#93132)
Fixes: https://github.com/vercel/next.js/issues/93126,
https://github.com/vercel/next.js/issues/95551
Repro:
- from `/` navigate to `/abc#foo`
- on `/abc#foo` - now click `/abc#bar`
- the url is now at `/abc#foo#bar`
Unlike, https://github.com/vercel/next.js/pull/93855, this PR fixes what
gets stored in the segment cache navigation, rather than slicing away an
existing hash. It is plausible that dropping the hash from the segment
cache is not desired though.
