fix: fix RUSTSEC-2026-0097 for rand 0.9

[va-an]

Fixes #269

Update transitive dependency rand from 0.9.2 to 0.9.3 via cargo update -p rand@0.9.2 to resolve RUSTSEC-2026-0097.

Note: #268 (rand 0.8.5 via secp256k1 and others) remains unaffected by this change and needs to be fixed upstream.

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 11.13%. Comparing base (07fd32f) to head (77dc466).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #270   +/-   ##
=======================================
  Coverage   11.13%   11.13%           
=======================================
  Files           8        8           
  Lines        2488     2488           
=======================================
  Hits          277      277           
  Misses       2211     2211           

Flag	Coverage Δ
rust	11.13% <ø> (ø)

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