Revert "feat(crypto): align NUT-20/29 signatures with spec change"

[a1denvalu3]

Reverts #1054

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.86%. Comparing base (eee256b) to head (0a58130).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1056      +/-   ##
==========================================
- Coverage   72.93%   72.86%   -0.07%     
==========================================
  Files         111      111              
  Lines       12395    12372      -23     
==========================================
- Hits         9040     9015      -25     
- Misses       3355     3357       +2     

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