Bump bl from 1.2.2 to 1.2.3 in /examples

Bumps [bl](https://github.com/rvagg/bl) from 1.2.2 to 1.2.3.
- [Release notes](https://github.com/rvagg/bl/releases)
- [Commits](rvagg/bl@v1.2.2...v1.2.3)

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

Author: dependabot[bot]