chore(deps): bump electrum-client from 0.18.0 to 0.22.0

Bumps [electrum-client](https://github.com/bitcoindevkit/rust-electrum-client) from 0.18.0 to 0.22.0.
- [Release notes](https://github.com/bitcoindevkit/rust-electrum-client/releases)
- [Changelog](https://github.com/bitcoindevkit/rust-electrum-client/blob/master/CHANGELOG.md)
- [Commits](bitcoindevkit/rust-electrum-client@0.18.0...0.22.0)

---
updated-dependencies:
- dependency-name: electrum-client
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>