Deprecation of `_v1` versions of AF_XDP structs

[arctic-alpaca]

The Linux kernel keeps _v1 versions of (some) updated structs for backwards compatibility with programs written for older kernel versions using AF_XDP. These older struct versions are not exposed via header and have to be skipped in the build.rs checking due to that. This means they cannot be automatically checked for changes or removal.

The newer versions of the deprecated structs work with older versions of the kernel, newer fields will be ignored/not filled.

This issue is linked in the deprecation notice in the code. Please comment here if you are using these structs.

[arctic-alpaca]

No deprecation as of now, see #4163