Bump sequencer from 02635b8 to 56c8769

Bumps [sequencer](https://github.com/EspressoSystems/espresso-sequencer) from `02635b8` to `56c8769`.
- [Release notes](https://github.com/EspressoSystems/espresso-sequencer/releases)
- [Commits](EspressoSystems/espresso-sequencer@02635b8...56c8769)

---
updated-dependencies:
- dependency-name: sequencer
  dependency-type: direct:production
...

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