feat(info): expose default network name

[kyounghunJang]

Description

This PR exposes the default network name in podman info output under networkBackendInfo.

Currently, the default network is usually podman, but users can customize this in containers.conf. Downstream tools (like Podman Desktop) and users need a way to programmatically determine what the current default network name is.

Fixes #27580

Checklist

Ensure you have completed the following checklist for your pull request to be reviewed:

• Certify you wrote the patch or otherwise have the right to pass it on as an open-source patch by signing all
  commits. (git commit -s). (If needed, use git commit -s --amend). The author email must match
  the sign-off email address. See CONTRIBUTING.md
  for more information.
• Referenced issues using Fixes: #00000 in commit message (if applicable)
• Tests have been added/updated (or no tests are needed)
• Documentation has been updated (or no documentation changes are needed)
• All commits pass make validatepr (format/lint checks)
• Release note entered in the section below (or None if no user-facing changes)

Does this PR introduce a user-facing change?

podman info now displays the name of the default network.

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: kyounghunJang
Once this PR has been reviewed and has the lgtm label, please assign honny1 for approval. For more information see the Code Review Process.

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

Needs approval from an approver in each of these files:

• OWNERS

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

[Honny1]

Hello, could you please remove the vendoring commit from this PR? If this requires a bump of common, I would suggest doing it in a separate PR.

[Luap99]

Thanks, you need to reorder your commits, the vendor commit should be first otherwise you break the build.

Also please squash the lint commit into the right commit, we don't want fixup commits on PRs as we merge commits as is.

[Luap99]

Hello, could you please remove the vendoring commit from this PR? If this requires a bump of common, I would suggest doing it in a separate PR.

Eh, we do vendoring all the time in the same PR with other changes, as long as you do it in separate commits that is fine.
Given this needs the common change doing it like this is fine.

[Honny1]

Hello, could you please remove the vendoring commit from this PR? If this requires a bump of common, I would suggest doing it in a separate PR.

Eh, we do vendoring all the time in the same PR with other changes, as long as you do it in separate commits that is fine. Given this needs the common change doing it like this is fine.

I got confused by the failed build. I didn't realize strict ordering was the issue. That's why I thought a separate PR was needed.

[Luap99]

#27612 did the vendoring for another feature so you can drop the vendor here and just add the podman test

[packit-as-a-service]

[NON-BLOCKING] Packit jobs failed. @containers/packit-build please check. Everyone else, feel free to ignore.

[kyounghunJang]

@Luap99 @Honny1
Thanks for the feedback! I’ve incorporated the suggested changes.