fix: update packit failure-notification team to new org

[mvanhorn]

The Packit failure-notification comment in .packit.yaml tagged @containers/packit-build, a team under the old containers org that no longer resolves now that the repo lives in podman-container-tools. As a result the mention is dead and maintainers are not pinged when Packit jobs fail.

This points the mention at @podman-container-tools/packit-build. The message is defined once on the &packit_generic_failure_notification YAML anchor (.packit.yaml line 56) and reused by reference on lines 71, 85, and 106, so the single edit covers every job that uses it. The individual @-handles on the Cockpit and tmt failure comments are untouched.

cc @lsm5 to confirm the exact team slug exists under the new org.

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?

None

Fixes #28882

[packit-as-a-service]

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

[danishprakash]

Afaict, no such team exists so far but even the old team only had @lsm5 so we can create it if needed.

[Honny1]

This group doesn't exist. The question is whether we want to tag someone or not. cc @lsm5

[Luap99]

@mvanhorn you already have two open PRs where you do not respond to any review feedback, if you are unable to engage in code review and make changes than please do not open further PRs until your existing PRs are done, either by merging or closing. Otherwise this just wastes our time.
And please note https://github.com/podman-container-tools/podman/blob/main/LLM_POLICY.md