chore(deps): bump gorm.io/driver/mysql from 1.5.4 to 1.5.6 in /engine

Bumps [gorm.io/driver/mysql](https://github.com/go-gorm/mysql) from 1.5.4 to 1.5.6.
- [Commits](go-gorm/mysql@v1.5.4...v1.5.6)

---
updated-dependencies:
- dependency-name: gorm.io/driver/mysql
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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