*: Use relative Jsonnet imports internally

[maxbrunet]

• I added CHANGELOG entry for this change.
• Change is not relevant to the end user.

Changes

• Use relative Jsonnet imports internally
• Disable jb's legacy imports (not used, but making sure they are not accidentally used in the future)

Reasons:

1. There is no guarantee kube-thanos/ is a valid import path for the end-user
2. These imports were relying on jb's legacy imports which are deprecated

Verification

CI passes.

[paulfantom]

Or you can use full import path of github.com/thanos-io/kube-thanos/jsonnet/kube-thanos/kube-thanos-receive-default-params.libsonnet which is guaranteed to be correct and allows to ditch legacy imports in jsonnet-bundler.

[maxbrunet]

That is how I use the library, but why would you do that in the library?
And it is still not guaranteed to work, for example here how it is installed in the repo itself:

kube-thanos/jsonnetfile.json

Lines 4 to 11 in e1a6859

	{
	"source": {
	"local": {
	"directory": "jsonnet/kube-thanos"
	}
	},
	"version": "."
	}

It create vendor/kube-thanos. It it not guarantee either that the user will use jb, especially that this library does not have any dependency. Another problematic case is if the user wants to use a fork, they need to rename those imports before being able to use it.

[maxbrunet]

@kakkoyun @metalmatze any concerns about merging this one if I rebase?

[risca-tec]

I have concern about this patch, since with relative imports would be much more hard to patch file at source without cloning the whole repository.
Instead using absolute import is much easier to override a specific file in order to apply custom patches. I usually play a lot with import paths, such as described here: https://tanka.dev/libraries/import-paths/