Migrate to `zcash_spec 0.1`

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (9a85034) 81.04% compared to head (4b09ef6) 80.91%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #413 +/- ## ========================================== - Coverage 81.04% 80.91% -0.14% ========================================== Files 31 30 -1 Lines 3166 3144 -22 ========================================== - Hits 2566 2544 -22 Misses 600 600 ```

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