Add support for capturing NT_GNU_ABI_TAG ELF note for glibc minimum supported Linux kernel version

[ermo]

It might prove useful to add this to a field in the glibc moss info output, such that we can programmatically check that glibc and kernels are compatible if users attempt to do weird moss it -d destdir installs in the future?

[sunnyflunk]

Looking at the glibc source. There seems to be kernel defines for version 5.9 and 5.14 (FUTEX_LOCK_PI2). It would make sense to standardize on one of those versions for clarity.

However, I don't think that this is worth it to cover edge cases (that may not even trigger from a small cli root) for running on an ancient system. Requirements can be stated that you need a recent kernel. If there becomes a real use case for something like this, it can only be fixed by lowering the kernel version in SOS.