Draft: treewide: remove *-openrc depends

postmarketos-base depends on alpine-base, which depends on openrc. This pulls in all *-openrc subpackages when their main packages get installed, so we don't need to add them as dependency.

See the install_if in abuild.in of default_openrc().

(postmarketos-ondev and related packages are not adjusted to avoid conflicts, will be done soon / tinydm + autologin will be upstreamed to alpine)