CI: fix artifact download pattern for multi-platform builds

Update bootstrap-test job to use pattern matching for bin artifacts
since they are now named bin-{os} due to the multi-platform matrix.

This fixes the artifact download that was looking for a single 'bin'
artifact which no longer exists after the CI generalization.

Author: dannywillems

.github/workflows/ci.yaml

@@ -500,7 +500,8 @@ jobs:
       - name: Download binary
         uses: actions/download-artifact@v4
         with:
-          name: bin
+          pattern: bin-*
+          merge-multiple: true
 
       - name: Download test
         uses: actions/download-artifact@v4