Fix bazel9 compatibility by explicitly loading cc_proto_library

[jasonkuster]

This change fixes protovalidate compatibility with bazel 9, which requires explicitly loading rules. Note that this does not change behavior when not using bazel 9, as the rule from cc_proto_library simply passes through to native.cc_proto_library (see implementation).

Also fix minor warning about setting a sha256 for the buf toolchain.

[CLAassistant]

All committers have signed the CLA.

[jasonkuster]

@srikrsna-buf I see you've reviewed prior PRs in this repo, mind taking a look at this very minor nit fix?

[rodaine]

Thanks for the patch, @jasonkuster! Looks like there's a lockfile that needs updating. make generate should do the trick.

[jasonkuster]

Fixed! Sorry for missing that :)

[srikrsna-buf]

Just needs the lockfile update otherwise looks good

[jasonkuster]

huh, my most recent commit does update the lockfile (I ran make generate and it produced a diff which I committed 🤔 ) Do you know if it's possible to get the lockfile diff from CI?

[jasonkuster]

Tried again and got a diff 🤷 so we can try CI again?

[rodaine]

That did the trick. Thanks again!