Merge pull request #367 from The-Strategy-Unit/fix_remove_pr_image

moves the removal of PR images into main pipeline

Author: tomjemmett

.github/workflows/build_container.yaml

@@ -87,8 +87,6 @@ jobs:
             ``` bash
             docker pull ghcr.io/the-strategy-unit/nhp_model:pr-${{ github.event.number }}
             ```
-
-            [Download Artifact](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }})
           edit-mode: replace
 
   deploy-ghcr:
@@ -163,4 +161,31 @@ jobs:
         if: ${{ inputs.latest }}
         run: |
           docker tag ${{ secrets.REGISTRY_LOGIN_SERVER }}/nhp_model:${{ inputs.docker-tag }} ${{ secrets.REGISTRY_LOGIN_SERVER }}/nhp_model:latest
-          docker push ${{ secrets.REGISTRY_LOGIN_SERVER }}/nhp_model:latest
+          docker push ${{ secrets.REGISTRY_LOGIN_SERVER }}/nhp_model:latest
+
+  remove-pr-image:
+    runs-on: ubuntu-latest
+    needs: ["deploy-ghcr"]
+    if: github.event_name == 'pull_request' && github.event.action == 'closed'
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - name: "Remove pr image"
+        env:
+          TAG_TO_DELETE: "pr-${{ github.event.pull_request.number }}"
+        run: |
+          VERSION_ID=$(gh api /orgs/the-strategy-unit/packages/container/nhp_model/versions \
+            -H "Accept: application/vnd.github+json" \
+            --paginate | \
+            jq -r '.[] | select(.metadata.container.tags[] == "$TAG_TO_DELETE") | .id')
+
+          if [ -n "$VERSION_ID" ]; then
+            echo "Deleting version ID: $VERSION_ID"
+            gh api \
+              -X DELETE \
+              /orgs/the-strategy-unit/packages/container/nhp_model/versions/${VERSION_ID} \
+              -H "Accept: application/vnd.github+json"
+          else
+            echo "Tag '$TAG_TO_DELETE' not found — skipping delete"
+          fi