ci: resolve merged PR number with bcgov/actions/image-tracker

[DerekRoberts]

merge.yml gets the merged PR number from the retiring bcgov/action-get-pr, and that number is the image tag for the TEST and PROD deploys.

Following the #202 migration guidance, the init job now uses bcgov/actions/image-tracker@79aefe3 (v0.9.0) and keeps its pr output, so needs.init.outputs.pr and every TEST and PROD tag stay the same. To work, image-tracker needs a checkout and packages: read. Nothing else changes, and no versions change.

Tag equivalence

How each one finds the number for a push to main:

• get-pr: asks the API (/commits/{sha}/pulls).
• image-tracker: reads (#N) from the squash subject (or the same API), then checks that GHCR has tag N for api, frontend and database. Its pr output is that N.

So the value matches, and image-tracker also fails before deploying if any of the three images is missing.

I ran image-tracker v0.9.0 locally against the last 12 commits on main and compared it with the get-pr API answer. All 12 matched:

Commit	get-pr	image-tracker
5b72f6e	679	679
cddfd50	678	678
8dcf802	677	677
82de285	675	675
cfb981e	674	674
ef42308	669	669
ff6d162	671	671
65d006c	666	666
2efca63	668	668
edfba10	672	672
835b1f6	667	667
f8cc297	665	665

workflow_dispatch runs on main resolve HEAD the same way.

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Thanks for the PR!

Deployments, as required, will be available below:

• Frontend
• API

Please create PRs in draft mode. Mark as ready to enable:

• Analysis Workflow

After merge, new images are deployed in:

• Merge Workflow

[Copilot]

🟢 Approval recommended

The action’s inputs and permissions match its requirements, and the downstream deployment output remains compatible.

No open issues 🎉

What changed in this PR

Replaces the retiring PR-number lookup action while preserving the image tags used for TEST and PROD deployments.

Changes:

• Uses image-tracker pinned to v0.9.0 to resolve the PR number and verify all three images.
• Adds checkout and package-read permission while retaining the existing pr output.

File	Description
.github/​workflows/​merge.yml	Migrates PR-number resolution to image-tracker with its required setup.

_{Review effort: Balanced}