[2.7-branch] ci: update download-artifact action to v4

[nashif]

v2 is deprecated and not supported anymore.

Signed-off-by: Anas Nashif anas.nashif@intel.com

[kartben]

However, this is a major update that includes breaking changes. Artifacts created with versions v3 and below are not compatible with the v4 actions. Uploads and downloads must use the same major actions versions. There are also key differences from previous versions that may require updates to your workflows.

Please also update upload-artifact versions otherwise it looks like we'll be in trouble :) (even if they do seem already out-of-sync in some places, e.g the codecov action, v4 seems to basically and very explicitly be incompatible with artifacts uploaded with older versions)

[cfriedt]

Could do uploads here or in a separate pr.

[kartben]

Could do uploads here or in a separate pr.

See my comment above. I would strongly recommend doing it in the same PR as GitHub explicitly says uploads from previous versions of the upload action DON'T work
https://github.blog/news-insights/product-news/get-started-with-v4-of-github-actions-artifacts/#compatibility