Move to vX.X.X tags for easier go module imports

[naemono]

closes #6134

These are the changes that I am aware of that would need to happen to prefix versions with v.

I'm unsure this is something we want to do this 2.6 release, but these are here for future release(s) when we want to pursue this.

Other changes needed

• ECK Download page Document needs updated to update the kubectl create -f https://download.elastic.co/downloads/eck/${VERSION}/crds.yaml links.

[thbkrkr]

The documentation would also be impacted by this change (#6284 (comment)).
What do you think about my proposal to minimize changes (#6134 (comment))?

[pebrc]

Should we get the necessary changes for this in with enough time to spare before the next release so that we can convince ourselves that everything works (release automation etc)?

[naemono]

Yes @pebrc I'll focus on this this upcoming week.

[naemono]

Wasn't able to get to this last week, but will work on this first thing this week to get these changes moving forward.

[naemono]

I've updated this PR with the discussed changes.

The documentation would also be impacted by this change (#6284 (comment)).

@thbkrkr I don't think these documentation changes are needed if we're not going to update the eck-attributes.asciidoc file with this v prefix:

:eck_version: v2.6.0

Right?

Also, I went through the operatorhub changes, and they will work as is, as we actually use the v prefix already for the name field, but ensure it's stripped for the version field in the rendered CSV:

# template
name: {{ .PackageName }}.v{{ .NewVersion }}
# rendered
name: elastic-cloud-eck.v2.6.0

...
# template
version: {{ .NewVersion }}
# rendered
version: 2.6.0

[thbkrkr]

LGTM

[thbkrkr]

Right?

Yes, it was not clear but it was a OR between my two sentences not a AND :)