qpdf: 8.0.2 -> 8.1.0 (#42684)

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.

These checks were done:

- built on NixOS
- /nix/store/razzvvhaim31v0qmv2f55y9w3659bdyy-qpdf-8.1.0/bin/fix-qdf passed the binary check.
- /nix/store/razzvvhaim31v0qmv2f55y9w3659bdyy-qpdf-8.1.0/bin/qpdf passed the binary check.
- /nix/store/razzvvhaim31v0qmv2f55y9w3659bdyy-qpdf-8.1.0/bin/zlib-flate passed the binary check.
- 3 of 3 passed binary check by having a zero exit code.
- 0 of 3 passed binary check by having the new version present in output.
- found 8.1.0 with grep in /nix/store/razzvvhaim31v0qmv2f55y9w3659bdyy-qpdf-8.1.0
- directory tree listing: https://gist.github.com/4bb6d8c7a59b4d3cfa1c78f0c45d9431
- du listing: https://gist.github.com/388a30c9e73f5667c8a8bb7a2740175e