Bump third_party/libdatachannel/repo from 73ac175 to 9e6a13a (project-chip#41073)

Bumps [third_party/libdatachannel/repo](https://github.com/paullouisageneau/libdatachannel) from `73ac175` to `9e6a13a`.
- [Release notes](https://github.com/paullouisageneau/libdatachannel/releases)
- [Commits](paullouisageneau/libdatachannel@73ac175...9e6a13a)

---
updated-dependencies:
- dependency-name: third_party/libdatachannel/repo
  dependency-version: 9e6a13abbb6846c003d817d0387b6706466e2b03
  dependency-type: direct:production
...

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Author: dependabot[bot]