Motivation for this change

Attempting to install haskellPackages.statgrab results in a compile time failure because the underlying statgrab C library was not found:

Setup: Missing dependency on a foreign library:
* Missing (or bad) header file: statgrab.h
* Missing C library: statgrab
This problem can usually be solved by installing the system package that
provides this library (you may need the "-dev" version). If the library is
already installed but in a non-standard location then you can use the flags
--extra-include-dirs= and --extra-lib-dirs= to specify where it is.
If the header file does exist, it may contain errors that are caught by the C
compiler at the preprocessing stage. In this case you can re-run configure
with the verbosity flag -v3 to see the error messages.

Things done

• Tested using sandboxing (nix.useSandbox on Nix
  OS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https
  ://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/) -- no binary executables generated from this
  package
• Fits CONTRIBUTING.md.

cc @peti