Bump truffle from 5.11.1 to 5.11.5 in /blockchain

Bumps [truffle](https://github.com/trufflesuite/truffle/tree/HEAD/packages/truffle) from 5.11.1 to 5.11.5.
- [Release notes](https://github.com/trufflesuite/truffle/releases)
- [Commits](https://github.com/trufflesuite/truffle/commits/[email protected]/packages/truffle)

---
updated-dependencies:
- dependency-name: truffle
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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