feat(tvix/castore): derive Eq and Hash automatically

This allows these messages to be put in HashSets.

Change-Id: Ia58094cafe53eb624578821d3d8d969c5d21a1d7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11219
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>

tvix/castore/build.rs

@@ -15,6 +15,7 @@ fn main() -> Result<()> {
     // https://github.com/hyperium/tonic/issues/908
     let mut config = prost_build::Config::new();
     config.bytes(["."]);
+    config.type_attribute(".", "#[derive(Eq, Hash)]");
 
     builder
         .build_server(true)