Better stack trace upon `Parallel::DeadWorker`

[KaanOzkan]

When the parent process is killed during parallel execution the stack trace is unhelpful https://github.com/Shopify/tapioca/issues/1555. Can we extract the underlying trace?

At the very least if we can't find the trace we should suggest this could be a OOM issue and suggest --workers flag.

[andyw8]

This would have helped for https://github.com/Shopify/tapioca/pull/1826.