Remove obsolete last invalidation keys

[adriansmares]

Summary

https://github.com/TheThingsNetwork/lorawan-stack/pull/4651 removes the ttn:v3:ns:application-uplinks:uid:<uid here>:last-invalidation keys from the application uplink queue. These keys are now unused, and may be deleted.

Why do we need this?

In order to avoid storing unused keys.

What is already there? What do you see now?

Keys of the form ttn:v3:ns:application-uplinks:uid:*:last-invalidation

What is missing? What do you want to see?

These keys should be deleted.

Environment

v3.15.0

How do you propose to implement this?

ns-db migrate takes care of the v3.10 -> v3.11 migration. This migration needs to be extracted in a separate function / file, and a new one that ranges through the invalidation keys and deletes them should be added.

How do you propose to test this?

Manually set the key and make sure that the migration deletes it safely.

Can you do this yourself and submit a Pull Request?

Yes.

[htdvisser]

Doesn't look like this is going to get finished for v3.17.0, so pushing to v3.17.1.

[NicolasMrad]

This is created a while ago, can you advise on the importance of this?

[adriansmares]

I would say this is still relevant and that we can write a short migration for this. Assigning @cvetkovski98 to take a look into this for the next minor - let me know if you need extra details.