fix(nix): set the goroot for tools like jetbrains

JetBrains needs to know the GOROOT environment variables. For the sake
of other tooling, we will just set these in the flake rather than only
in the `.envrc` file. It also keeps all environment configuration
localized to our project flake.

flake.nix

@@ -20,6 +20,11 @@
           nodePackages.prettier
           infisical
         ];
+
+        env = {
+          GOROOT = "${pkgs.go}/share/go";
+          GOPATH = "$(pwd)/.go";
+        };
       };
   };
 }