pdfgrep: 2.1.0 -> 2.1.1 (#41048)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/pdfgrep/versions.

These checks were done:

- built on NixOS
- /nix/store/x24n7dayjdzkr7spig1qvhq9vadgswyh-pdfgrep-2.1.1/bin/pdfgrep passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 2.1.1 with grep in /nix/store/x24n7dayjdzkr7spig1qvhq9vadgswyh-pdfgrep-2.1.1
- directory tree listing: https://gist.github.com/f441dd82cfb9701f3e9ae1fc9653b4f0
- du listing: https://gist.github.com/23df51a35a4e7e35c11787490219aea1