fix(trigger-coolify-deploy): guard collateral-cancel status query

[Andreas-Garcia]

Summary

• After cancel_phantom_builds() cancels a native build, the follow-up mine_status=$(curl -sf ...) check (to detect whether that collaterally cancelled our own just-queued deployment) had no error handling, unlike the near-identical query inside cancel_phantom_builds() itself.
• Under the script's top-level set -euo pipefail, a non-2xx response from that GET (curl exit 22) hard-failed the whole deploy step instead of gracefully falling through.
• Found while diagnosing PR #253 in the-music-deck-admin's "Deploy API (preview)"/"Deploy showcase" checks failing with Process completed with exit code 22 right after Deployment queued: ... / Checking for a still-running native (webhook-triggered) preview build to stop....

Changes

• Wrap the mine_status query in set +e / capture exit status / set -e, same pattern as cancel_phantom_builds()'s own query.
• On query failure, log a warning and treat mine_status as empty (i.e. assume not collaterally cancelled) rather than aborting.
• Changelog entry under [Unreleased] / Fixed.

Test plan

• Script-only error-handling fix, no new testable behavior beyond existing coverage.
• Will re-trigger PR #253's "Deploy API (preview)" / "Deploy showcase" checks against this fix once merged/tagged to confirm the step no longer hard-fails on this call.