[aur-general] Deletion request: graphviz-hg

[Techlive Zheng]

The source URL in the package [graphviz-hg][1] is dead, and graphviz
is now using Git as VCS, a new package is created at
[graphviz-git][2].

[1]: https://aur.archlinux.org/packages/graphviz-hg/
[2]: https://aur.archlinux.org/packages/graphviz-git/