Changing the IPA compression algorithm and updating the IPA image tag to use new compressed images

[claudia-lola]

Updates the IPA (Ironic Python Agent) compression algorithm from the default gzip to use instead zstd -19. This change will reduce the transfer size of the IPA boot ISO from the Ironic conductor to the baremetal nodes during provisioning. The IPA image tag has been updated to reference the new compressed IPA images.

[gemini-code-assist]

Code Review

This pull request updates the Ironic Python Agent (IPA) image compression to use zstd for smaller image sizes, and updates the corresponding image tags. The changes are straightforward and correctly implement the switch to zstd compression. I have one minor suggestion in etc/kayobe/ipa.yml to improve the conciseness of the command. Also, there's a small typo ('alogrithm') in the pull request title.

[Alex-Welsh]

@claudia-lola the IPA images were just rebuilt and updated in another PR: #1909

Could you please rebase your changes on the latest version of stackhpc/2025.1, then rebuild the images and update the tags?

Also, this change needs a release note.

If you need a hand with any of that, just let me know

[priteau]

Hi @claudia-lola. Can you please rebase your changes instead of merging from stackhpc/2025.1? You can also squash all your changes into a single commit.