Merge branch 'selftests-net-groundwork-for-ynl-based-tests'

Jakub Kicinski says:

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selftests: net: groundwork for YNL-based tests (YNL prep)

v1: https://lore.kernel.org/all/20240402010520.1209517-1-kuba@kernel.org/
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Merge the non-controversial YNL adjustment and spec additions.

Link: https://lore.kernel.org/r/20240403023426.1762996-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>