perf: tuck away imports not needed to display cli help

[joanise]

See EveryVoiceTTS/EveryVoice#783

[semanticdiff-com]

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Changed Files

File	Status
fs2/cli/synthesize.py	0% smaller

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 49.64%. Comparing base (582ca8b) to head (808714c).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
fs2/cli/synthesize.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #134      +/-   ##
==========================================
- Coverage   49.69%   49.64%   -0.06%     
==========================================
  Files          27       27              
  Lines        1986     1986              
==========================================
- Hits          987      986       -1     
- Misses        999     1000       +1     

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