📖 book: remove old versions from versions.md

[sbueringer]

Signed-off-by: Stefan Büringer [email protected]

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Follow-up to: #8134 (comment)

[sbueringer]

/assign @fabriziopandini @vincepri

[sbueringer]

/assign @oscr @elmiko

[oscr]

Nice cleanup! Thank you for your hard work

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 9c24b6ef167edcc1ea746bbffb87e7764b9e8ba9

[fabriziopandini]

Thanks for following up on my comment after the previous PR merged, really appreciated.
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: fabriziopandini

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• docs/OWNERS [fabriziopandini]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[sbueringer]

/cherry-pick release-1.3

[k8s-infra-cherrypick-robot]

@sbueringer: new pull request created: #8175

In response to this:

/cherry-pick release-1.3

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.