Bump bl from 1.2.1 to 1.2.3 (#320)

Bumps [bl](https://github.com/rvagg/bl) from 1.2.1 to 1.2.3.
- [Release notes](https://github.com/rvagg/bl/releases)
- [Commits](rvagg/bl@v1.2.1...v1.2.3)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]