release.nix use makeBinPath to construct PATH

Dependencies

• [2] LOHWNXEJ Cleanup
• [3] M4JUF5V6 Drop obsolete graphviz dependency
• [4] WTHZ4AGP hydra: remove some layout, test
• [5] T4LLYESZ * Nix expression for building Hydra.
• [6] SAFVRDTK * Put Hydra's dependencies so that they can easily be installed in a
• [7] 6K5PBUUN Use buildEnv to combine Hydra's Perl dependencies
• [8] L7RW467Z Add a test for darcs inputs.
• [9] YQWH4POV * Simplify.

Change contents

• replacement in release.nix at line 136
  [3.1305]→[2.303:348](∅→∅)
  − hydraPath = lib.makeSearchPath "bin" (
  [3.1305]

  [2.348]
  + hydraPath = lib.makeBinPath (