Bun.$ should keep the Bun process alive while a command is running

[Jarred-Sumner]

What does this PR do?

Fixes #12679

The following two scripts exit with exit code 1 but they should exit with exit code 0.

process.exitCode = 1;

(async () => {
  await Bun.$`ls .`;
  process.exit(0);
})();

process.exitCode = 1;

(async () => {
  await Bun.$`${process.execPath} -e "console.log('hi')"`;
  process.exit(0);
})();

How did you verify your code works?

There is a test

[github-actions]

❌ @Jarred-Sumner, your commit has failing tests :(

💪 1 failing tests Darwin AARCH64

• test/js/web/workers/worker.test.ts 1 failing

💻 1 failing tests Darwin x64 baseline

• test/js/node/http/node-http.test.ts 1 failing

💻 1 failing tests Darwin x64

• test/cli/hot/hot.test.ts 1 failing

🪟💻 3 failing tests Windows x64 baseline

• test/cli/install/registry/bun-install-registry.test.ts 2 failing
• test/js/bun/shell/shell-keepalive.test.ts 1 failing
• test/js/node/child_process/child_process.test.ts 1 failing

View logs

[zackradisic]

lgtm