This reverts commit e477777f49.
In principle, we could have stayed with `~1.21.1`, but `check-latest:
true` apparently checks some cache/manifest/something that is only
periodically refreshed and isn't aware of 1.21.5 yet. So update the
constraints to force an upgrade.
Also the infrastructure images weren't actually using the constraint
since there was no `setup-go` action...
### Purpose
The OCI image spec specifies well-defined
[annotations](https://github.com/opencontainers/image-spec/blob/main/annotations.md)
that can be added to images.
Theses annotations can then be used by other tools to gather more
information of an image.
This PR adds the `org.opencontainers.image.source` to allow tools such
as [renovate](https://github.com/renovatebot/renovate) to find the
release notes of a give version.
~~I've only done this change for `Dockerfile`. Should I also add the
label to the other dockerfiles?~~
I've now added the source annotations to all `Dockerfile`s & action
workflows.
### Testing
None, change was done by following the [renovate
documentation](https://docs.renovatebot.com/modules/datasource/docker/).