chore(3p): Bump channels to 2021-04-09 r/2481

Fixes included:

* exposed gtest in the package set, required for protobuf
* pinned SBCL to version 2.0.8: The channel moved it to >2.1, and a
  bunch of warnings seemed to be killing our builds - we should
  investigate this later.
* removed kernel patches from //users/tazjin/frog: this machine is
  currently out of service anyways, not worth fixing while it's offline
* removed steam & lutris from frog (they're currently broken)
* removed Haskell overrides for hedgehog-classes & hgeometry-combinatorial
* use gRPC sources from upstream and inject Abseil via Nix instead
* fix for renamed grpc import in //third_party/nix
* use libfprint-tod from upstream nixpkgs in glittershark/yeren and
  delete glittershark/pkgs/fprintd entirely, since all of the patches used
  there are available and working from upstream now (and stopped working
  here after the bump)

Change-Id: Ia90e6f774f7b88bc9e60d28351b900ca43ee2695
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2901
Reviewed-by: glittershark <grfn@gws.fyi>
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions