[ci] Keep the alias registered during an LSU status flip

[ray-roestenburg-da]

Between a generation going LSU_SOURCE and its successor going ACTIVE no generation is active, so a psid-less lookup reported the alias as unregistered and failed SV app init.

Fixes https://github.com/DACH-NY/cn-test-failures/issues/9447

Pull Request Checklist

Cluster Testing

• If a cluster test is required, comment /cluster_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If an upgrade test is required, comment /upgrade_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a hard-migration test is required (from the latest release), comment /hdm_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a logical synchronizer upgrade test is required (from canton-3.5), comment /lsu_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.

PR Guidelines

• Include any change that might be observable by our partners or affect their deployment in the release notes.
• Specify fixed issues with Fixes #n, and mention issues worked on using #n
• Include a screenshot for frontend-related PRs - see README or use your favorite screenshot tool

Merge Guidelines

• Make the git commit message look sensible when squash-merging on GitHub (most likely: just copy your PR description).

[moritzkiefer-da]

not obvious to me that this is correct, I'll try to take a look at the logs next week to see what makes sense

[ray-roestenburg-da]

Thanks @moritzkiefer-da !