scripts: add ignore-not-found for undeploy and uninstall to Makefile boiler plate

[sgaist]

Description of the change:

This PR adds the --ignore-not-found parameter to the kubectl call when calling make undeploy and make uninstall.

Motivation for the change:

This avoid the failure of either command if for some reason one or more of the kustomized resource is missing.

Part of #5195

Checklist

If the pull request includes user-facing changes, extra documentation is required:

• [X] Add a new changelog fragment in changelog/fragments (see changelog/fragments/00-template.yaml)
• [X] Add or update relevant sections of the docs website in website/content/en/docs