Revert "Depend on the cogl-path-1.0 pkg-config file"

This reverts commit b6fc4a810f2f3437d5478241a6e6ff2aa43cf0b4.

It seems that the Cogl/Cogl-Path split was not meant to break API/ABI,
so we should not check for a new dependency. Let's revert the commit,
and wait for Cogl to get fixed instead.