Fetch Tags in CI action for changelog

[aaruni96]

Fetch Tags in CI action for changelog
[skip ci]

[aaruni96]

This change doesn't seem to help ( https://github.com/oscar-system/Oscar.jl/actions/runs/13184942801/job/36804728541 ). Documentation ( https://github.com/actions/checkout ) suggests this should've worked :

    # Whether to fetch tags, even if fetch-depth > 0.
    # Default: false
    fetch-tags: ''

Any ideas how to proceed @fingolfin

[fingolfin]

Actually we probably don't need to fetch the tags at all. Indeed basetag is only needed as input for get_tag_date. But we can just query gh for that.

$ gh release view v1.2.2 --json=createdAt
{
  "createdAt": "2024-12-13T22:47:54Z"
}