⬆️ Bump libs/parallel-hashmap from 56a2e53 to a68a9b5 (cda-tum#213)

Bumps [libs/parallel-hashmap](https://github.com/greg7mdp/parallel-hashmap) from `56a2e53` to `a68a9b5`.
- [Release notes](https://github.com/greg7mdp/parallel-hashmap/releases)
- [Commits](greg7mdp/parallel-hashmap@56a2e53...a68a9b5)

---
updated-dependencies:
- dependency-name: libs/parallel-hashmap
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]