just update-deps capnp-cpp

[mikea]

Brings in all recent optimizations

[ask-bonk]

The change is straightforward:

1. Only one file changed (build/deps/gen/deps.MODULE.bazel) — bumps the capnp-cpp archive from commit 84928ed to 55ba056.
2. No patches exist for capnp-cpp in this repo, so there's no patch compatibility concern.
3. The new commit exists upstream and the sha256 hash is updated accordingly.
4. The upstream delta is 4 commits: emplaceInit functions, bazel config checks, ExceptionOr<T> operator= optimization, and a benchmark dependency revert — all non-breaking library-internal changes.
5. The strip_prefix correctly matches the new short hash (capnproto-capnproto-55ba056).

No logic bugs, no security issues, no backward compat concerns, no missing compat flags, no schema changes.

LGTM

github run