Use sus runner binary (not -rsus) to get describe in scope

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: samuel-williams-shopify

.github/workflows/test-ruby-gc-bug.yaml

@@ -108,7 +108,7 @@ jobs:
           cd $GITHUB_WORKSPACE
 
           echo "=== Running worker_pool test with ruby-${variant} ==="
-          (timeout 60 ruby -I lib -I fixtures -I /tmp/ext-${variant} -rsus \
+          (timeout 60 sus -I lib -I fixtures -I /tmp/ext-${variant} \
             test/io/event/worker_pool.rb 2>&1 | tail -10; echo "exit_${variant}:$?") || true
           echo "--- end ${variant} ---"
         done