ci: restore upgrade-test (lifecycle) as a promotion gate once GNOME 50 AT-SPI is stable

[castrojo]

Context

post-testing-e2e.yml runs a lifecycle (upgrade & rollback) suite via
projectbluefin/actions/.github/workflows/upgrade-test.yml. The lifecycle suite
is failing under GNOME 50 AT-SPI changes (see run
27075323936,
job: GNOME 50 — lifecycle).

In PR #399 the run-upgrade-test job was decoupled from the promote-to-testing
and report-failure gates so that lifecycle test failures don't block the
continuous promotion of :testing or the weekly promotion workflow. The job
still runs and uploads results artifacts.

Steps to restore

1. Investigate and fix the lifecycle test failures in projectbluefin/testsuite
   (GNOME 50 AT-SPI changes documented in the bluefin-ci skill and testsuite ops.md).
2. Once lifecycle scenarios pass consistently in CI, restore run-upgrade-test to
   the promote-to-testing and report-failure needs: arrays in
   .github/workflows/post-testing-e2e.yml.
3. Also restore the gate condition:

   if: >-
     needs.run-e2e.result == 'success' &&
     needs.run-upgrade-test.result == 'success'

4. Remove the TODO comment from run-upgrade-test.

Labels

area/testing, kind/bug

Bluefin · issue pipeline

  ▶  triage     needs kind/ + area/ then /approve
  ·  discussing —
  ·  queued     —
  ·  claimed    —
  ·  done       —

area: area/testing   priority: —
maintainer: set kind/ + area/ labels, then comment /approve
reporter: answer questions; add repro steps if a bug

[castrojo]

The post-testing-e2e.yml workflow already has run-upgrade-test disabled with # TODO(#400) and a clear comment explaining the blocker (GNOME 50 AT-SPI changes). The steps to restore it are documented in the issue body.

This issue remains open and tracks the upstream work: once lifecycle scenarios pass consistently in projectbluefin/testsuite under GNOME 50, the job can be re-enabled by restoring it to the needs: arrays in post-testing-e2e.yml. No in-repo code change can unblock this — it requires the testsuite fix first.