Use Valkey-swift instead of Redistack

[adam-fowler]

This is a draft until we release v0.1.0 of valkey-swift

[codecov]

Codecov Report

❌ Patch coverage is 94.76440% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.37%. Comparing base (0a697d0) to head (895d026).

Files with missing lines	Patch %	Lines
Sources/JobsValkey/ValkeyJobQueue.swift	91.13%	7 Missing ⚠️
Sources/JobsValkey/ValkeyJobQueue+cleanup.swift	90.32%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #47      +/-   ##
==========================================
+ Coverage   91.99%   93.37%   +1.38%     
==========================================
  Files           7        5       -2     
  Lines         587      438     -149     
==========================================
- Hits          540      409     -131     
+ Misses         47       29      -18     

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