x11-fonts/google-fonts: revert "Remove expired port"

This reverts commit 77c04acae3e7847e6f41009ad05e44225c462dd2.

Update the port to not reference the now removed x11-fonts/gentium-basic
and the expiring x11-fonts/open-sans. Referencing the latter caused
poudriere bulk to fail.

Remove deprecation notice.

Requested by: des