qpdf: 8.1.0 -> 8.2.1

Semi-automatic update generated by
https://github.com/ryantm/nixpkgs-update tools. This update was made
based on information from
https://repology.org/metapackage/qpdf/versions.

pkgs/development/libraries/qpdf/default.nix

···
 { stdenv, fetchurl, fetchpatch, libjpeg, zlib, perl }:
 
-let version = "8.1.0";
+let version = "8.2.1";
 in
 stdenv.mkDerivation rec {
   name = "qpdf-${version}";
 
   src = fetchurl {
     url = "mirror://sourceforge/qpdf/qpdf/${version}/${name}.tar.gz";
-    sha256 = "1m3hcgip6bzjx4gd7wq1328p8zi3pq5savzncdyln6l0lcklh7vx";
+    sha256 = "1jdb0jj72fjdp6xip4m7yz31r5x13zs7h4smnxsycgw3vbmx6igl";
   };
 
   nativeBuildInputs = [ perl ];