ci : fix dry-run reporting in make-release job [no ci] (#27167)

This commit fixes the reporting in the make-release CI job when
--dry-run is used. It will currently incorrectly report that all checks
pass even if there are steps that fail.

Refs: https://github.com/ggml-org/llama.cpp/pull/26839#issuecomment-5306189828

.github/workflows/make-release.yml

@@ -42,5 +42,10 @@ jobs:
       - name: Dry run summary
         if: ${{ github.event.inputs.dry_run == 'true' }}
         run: |
-          echo "Dry run complete - all checks passed."
-          echo "Would have created tag: ${{ steps.checks.outputs.version }}"
+          if [[ "${{ steps.checks.outputs.checks_passed }}" == "true" ]]; then
+            echo "Dry run complete - all checks passed."
+            echo "Would have created tag: ${{ steps.checks.outputs.version }}"
+          else
+            echo "::error::Dry run found release check failures. A release tag would not be created."
+            exit 1
+          fi