egl,glx,gbm: Bump loaders' DRI driver version requirements to what we implement.

Now that we only plan to support loading drivers from in tree (if you want to mix and match old drivers, you're expected to use glvnd and the amber branch or something similar), we can bump a bunch of dri_interface version requirements.

This isn't that many lines of code reduced, but I hope we can follow up with collapsing a bunch of Mesa-internal extensions into one big vtable that we guarantee is always present.