Use imgpkg for listing available images

[alexandreroman]

What this PR does / why we need it

Since imgpkg is part of the Carvel toolsuite which is heavily used by TCE, use this tool instead of crane.

[vmwclabot]

@alexandreroman, you must sign our contributor license agreement before your changes are merged. Click here to sign the agreement. If you are a VMware employee, read this for further instruction.

[github-actions]

Hi @alexandreroman! And thank you for opening your first Pull Request. Someone will review it soon. Thank you for committing to making Tanzu Community Edition better.

[stmcginnis]

Thanks @alexandreroman - could you edit the PR description with a little more context as to why to switch these?

[alexandreroman]

Since imgpkg is part of the Carvel toolsuite (heavily used by TCE), I find more appropriate to use this tool instead of crane.

[joshrosso]

@alexandreroman to get this merged, we do need your signature for CLA, the bot above has instructions.

Thanks!

[alexandreroman]

Do I need to sign the CLA as a VMware employee?

[stmcginnis]

Do you have your VMware email address associated with your GitHub account? The CLA bot should be able to recognize that and tag this as not needing the CLA signed. Verify under your account settings, and if you do have it listed then you may need to bring it up with the OSPO team that maintains this bot.

[seemiller]

@alexandreroman Have you ever completed the CLA so that we can merge this PR?

[alexandreroman]

@alexandreroman Have you ever completed the CLA so that we can merge this PR?

I did!