Remove GitLab Pages for alpm-types

alpm-buildinfo and alpm-types have been consolidated into the alpm
project[1], for which GitLab Pages was recently configured[2][3].

Requested by @dvzrv.

[1] https://gitlab.archlinux.org/archlinux/alpm/alpm
[2] archlinux/alpm/alpm#32
[3] 3d54b56c ("Add GitLab Pages for alpm")