Add dependency on nix-perl

Dependencies

• [2] 34UH6B6L Build against the bleeding edge of Nix
• [3] UGA45FNC Add a plugin for backing up builds in s3
• [4] 67QM2R5C Depend on Term::Size::Any
• [5] X7IAG7JT Simplify running nix-shell
• [6] 6K5PBUUN Use buildEnv to combine Hydra's Perl dependencies
• [*] T4LLYESZ * Nix expression for building Hydra.

Change contents

• replacement in release.nix at line 112
  [3.1145]→[2.1017:1058](∅→∅)
  − nix git boehmgc aws-sdk-cpp'
  [3.1145]

  [3.1165]
  + nix

  + nix.perl-bindings

  + git

  + boehmgc

  + aws-sdk-cpp'