Merge bitcoindevkit/bdk#863: Fix ci Dockerfile.ledger

5b9e0e392a246b7cafa3fa6836be7603b039bad7 Fix ci Dockerfile.ledger (Steve Myers)

Pull request description:

  ### Description

  Ledger emulator used to default to `-model nanos` but in latest release we need to add it to the command line. This change fixes `test_hardware_wallet` CI tests.

  ### Notes to the reviewers

  I originally made this fix in the `release/0.27` branch, this PR cherry-picks the change back to the `master` branch. I should have done a `master` branch PR first but it's only a CI change and I wanted to get the `0.27.0` release out.

  ### Changelog notice

  None.

  ### Checklists

  #### All Submissions:

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

ACKs for top commit:
  danielabrozzoni:
    tACK 5b9e0e392a246b7cafa3fa6836be7603b039bad7

Tree-SHA512: 552586dc614d11c4084b73ad865078c9e28a1bdd3eda9addc8055df6408bba5f110f8aa7b3da730949f41cfd48f87b12cda0ba2df2b98e40e1590aa99b54a7ee