I'm trying to write an overlay for a PyPI package normally not available via `python3.withPackages`, but the download fails with a 404 on a URL. When visited manually, the PyPI download section features a tarball URL with a link containing the SHA. What am I doing wrong?
```nix
(self: super:
  {
    python3 = super.python3.override {
      packageOverrides = self: super: {
        pdfplumber = super.buildPythonPackage rec {
          pname = "pdfplumber";
          version = "0.52.1";
          doCheck = false;
          src = super.fetchPypi {
            inherit pname version;
            sha256 =
              "ba4cf6287aa6d075f8c9cf64aa93f364e15c7583085c2ec4a33bb02b0130740d";
          };
        };
      };
    };
  })
```