chore(turbopack): Bump rustc-hash from 2.1.0 to 2.1.1 (#78721)

This includes rust-lang/rustc-hash#56

Apparently 2.1.0 has a bug that can cause lots of hashtable collisions for very large maps with more than `2^20` elements. We have some very large maps, so this seems potentially concerning.

Author: bgw