bibutils: 6.2 -> 6.3

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

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

These checks were done:

- built on NixOS
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/bib2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/biblatex2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/copac2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/end2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/endx2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/isi2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/med2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/nbib2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/ris2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/ebi2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/wordbib2xml passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2ads passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2bib passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2end passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2isi passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2ris passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/xml2wordbib passed the binary check.
- /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3/bin/modsclean passed the binary check.
- 18 of 18 passed binary check by having a zero exit code.
- 0 of 18 passed binary check by having the new version present in output.
- found 6.3 with grep in /nix/store/wi9d6xxy76775jkzlqmy6fp4pm2kikdn-bibutils-6.3
- directory tree listing: https://gist.github.com/ff41347f63c0154c5f7b0322829c0001
- du listing: https://gist.github.com/2121b0f7644516ee8febcabcb1928da5