Updating private registry support to handle private dockerhub images

[cdchris12]

Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for changelog and subsystem label(s) applied

This PR adds support for private docker hub images to kubectl-build-deploy-dind, as this support is non functional at the moment due to a hardcoded dependency on the imagecache

Closing issues

Put closes #XXXX in your comment to auto-close the issue that your PR fixes (if such).

[shreddedbacon]

Have done some testing with the environment reporting the issue using the latest image built by jenkins

testlagoon/kubectl-build-deploy-dind:pr-2516@sha256:020e5623c7e4eff8bde590b2aa2cc0953bee100864c149f2e5978fdb69f46aeb

The environment was able to successfully pull the image from private registry and push to harbor using skopeo, where before it would fail due to imagecache.

We also ran it through a drupal example site in another cluster and it completed successfully, with no private registries defined, it used the imagecache as it was supposed to.

[tobybellwood]

@cdchris12 - if this needs to make it to Lagoon in the next few weeks, this PR will need to be repointed to the master branch instead of main before we release 1.14 (as 1.14 is a Lagoon 1-only release)

[cdchris12]

@tobybellwood I've actually already backported this, I just tagged the wrong PR for release in 1.14 :(

You'll want to merge #2517 instead. It's the same code, just applied to the master branch instead of the main branch

[tobybellwood]

Sorry; this is my mistake. :( I'll push up a fix for 1.x so we can at least get this sorted

adds to the list of things we should probably have tests for, but don't 😬