chore(3p/nix): don't rebuild nix-proto-srcs as much r/1380

Interpolating a path into a string will copy the referenced path into
the Nix store, so this got a dependency on all of src.  By first
constructing a path to the src/proto directory using the + operator,
and then interpolating it, we limit what is copied to the store, and
therefore what code triggers a nix-proto-srcs rebuild.

Change-Id: I8dd750f6bc5902b74ffb56470bc8a5f2c01c8cf1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1263
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>
Reviewed-by: tazjin <mail@tazj.in>

0 files changed, 0 insertions, 0 deletions