Bump capnpc from 0.16.1 to 0.16.3

Bumps [capnpc](https://github.com/capnproto/capnproto-rust) from 0.16.1 to 0.16.3.
- [Release notes](https://github.com/capnproto/capnproto-rust/releases)
- [Commits](capnproto/capnproto-rust@capnpc-v0.16.1...capnpc-v0.16.3)

---
updated-dependencies:
- dependency-name: capnpc
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]