Merge bitcoindevkit/bdk-cli#270: fix: fix RUSTSEC-2026-0097 for rand 0.9

77dc466ca54eb8466e8670428c384fc34c6a81ac chore: update rand 0.9.2 -> 0.9.3 (Vadim Anufriev)

Pull request description:

  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:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk-cli/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

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