libnftnl: add new recipe (#26198)

[nikitasinys]

Summary

Add new recipe: libnftnl/[1.2.8], fixes #26198

Motivation

This library helps to work with nf_tables subsystem

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• Read the contributing guidelines
• Checked that this PR is not a duplicate: list of PRs by recipe
• Tested locally with at least one configuration using a recent version of Conan

[valgur]

Thanks! LGTM. The Windows shared validation needs to be moved to validate().

[nikitasinys]

Thanks! LGTM. The Windows shared validation needs to be moved to validate().

Thanks for review!

[nikitasinys]

Hi @conan-io/barbarians,
I have an hanging pre-check for 20 days in two of my PR (this PR and #26204), it's also still hanging after adding new commits
Can you please look at it?

[nikitasinys]

Hi @uilianries
I have an issues with hanging pre-checks for more than a month in two of my PR, I tried to ping @conan-io/barbarians but probably mentioning didn't worked. Can you please look at it?

Hi @conan-io/barbarians, I have an hanging pre-check for 20 days in two of my PR (this PR and #26204), it's also still hanging after adding new commits Can you please look at it?

[uilianries]

@nikitasinys An internal error occurred when running your PR. I just reported internally to take action. Sorry for the occurrence.

[uilianries]

@nikitasinys An internal hotfix is now running over your PR and fixed your previous error. Still, the requirement libmnl has a small bug in still recipe which is breaking the continuation of the CI too. The PR #26542 should address it. Sorry for the inconvenience again.