Upgrade to twox-hash 2.0

[shepmaster]

Thanks for using my crate!

Note that version 2.0 increases the MSRV to Rust 1.81. I understand if you don't want to upgrade right away, but hopefully this PR will be useful when you do.

I'm opening these PRs for the top users of twox-hash and have no current plans to become a consistent contributor to this specific repository; please feel free to rewrite the commit as appropriate for your project's requirements.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.45%. Comparing base (0c7f83e) to head (cf7caa8).
Report is 146 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #937      +/-   ##
==========================================
+ Coverage   81.43%   81.45%   +0.01%     
==========================================
  Files          97       97              
  Lines       23877    24930    +1053     
==========================================
+ Hits        19445    20307     +862     
- Misses       4432     4623     +191     

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[bartlomieju]

Thanks @shepmaster, can you please sign the CLA so we can land this PR?