`mkShellArgs.packages` does not work

An application I'm writing uses an SQLite database, so I wanted to include the sqlite3 executable in the nix develop shell. I passed sqlite-interactive through mkShellArgs and the package is added to the nix store, but the PATH variable is not updated. My flake.nix looks like

{
  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      systems = nixpkgs.lib.systems.flakeExposed;
      imports = [ inputs.haskell-flake.flakeModule ];

      perSystem = { self', pkgs, ... }: {
        haskellProjects.default = {
          packages = { };
          devShell = {
            tools = hp: { };
            mkShellArgs = {
              packages = [ pkgs.sqlite-interactive ];
            };
          };
        };

        packages.default = self'.packages.imgr;
      };
    };

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
    haskell-flake.url = "github:srid/haskell-flake";
  };
}

I currently use a shellHook as a work-around:

shellHook = "export PATH=$PATH:${pkgs.sqlite-interactive}/bin"

Start with the mkShellArgs configuration in the reported flake.nix and reproduce the issue with nix develop. Trace how packages is passed into the development shell, then verify that the resulting shell PATH includes the sqlite3 executable without relying on shellHook.