feat(tvix/store/protos): add CA field r/6870

This adds support to represent the `CA` field found in some .narinfo
files. As `deriver`, it's also a subfield of the `narinfo` field.

Extending nix-compat with a more accessible data structure that can
take care of formatting, as well as writing validation functions in Rust
+ Golang, and integrating it into nar-bridge is something for a followup
CL.

Change-Id: I71e9c30957bcd03051a491aa54d7baac25b6dd2d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9795
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>

0 files changed, 0 insertions, 0 deletions