Fix TXE SIGTERM handling for dump_fail compatibility #12318

Description

I noticed a TODO comment in the bootstrap.sh file:

# TODO: I'd like to use dump_fail here, but TXE needs to exit 0 on receiving a SIGTERM.
(cd $root/yarn-project/txe && LOG_LEVEL=silent TXE_PORT=$((45730 + i)) retry yarn start) &>/dev/null &

This comment indicates that the TXE service doesn't properly handle SIGTERM signals, preventing the use of the dump_fail utility for better error handling.

Proposed Solution

I'd like to implement a simple fix by adding a SIGTERM handler to the TXE service that ensures it exits with code 0 when receiving this signal. This would allow the bootstrap.sh script to use dump_fail for TXE execution, improving error handling and debugging.

The changes would be minimal:

1. Add a SIGTERM handler in yarn-project/txe/src/bin/index.ts
2. Update bootstrap.sh to use dump_fail for TXE execution

Question

Would this change be welcome? I'm happy to submit a PR with these changes if it aligns with the project's goals.