Bump ismp-testsuite from 711fd0c to 1553fc6

Bumps [ismp-testsuite](https://github.com/polytope-labs/hyperbridge) from `711fd0c` to `1553fc6`.
- [Release notes](https://github.com/polytope-labs/hyperbridge/releases)
- [Commits](polytope-labs/hyperbridge@711fd0c...1553fc6)

---
updated-dependencies:
- dependency-name: ismp-testsuite
  dependency-type: direct:production
...

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