fix(create-turbo): Prevent hang when using bun package manager (#11386)
## Summary
Fixes #11343
When running `bunx create-turbo@latest` and selecting Bun as the package
manager, the CLI would hang after creating the project directory and
files successfully.
## Root Cause
The `install` function in `@turbo/workspaces` uses `execa` to run the
package manager's install command. By default, `execa` inherits stdin
from the parent process. When running via `bunx`, this causes `bun
install` to hang waiting for stdin input that never comes.
## Solution
Added `stdin: "ignore"` to the `execa` call in the install function.
This prevents the child process from inheriting stdin and waiting for
input.
This pattern was already being used elsewhere in the codebase:
- `utils.ts` for `bunLockToYarnLock`
- `pnpm.ts` for `pnpm import`
## Test Plan
- Added parameterized test to verify `stdin: "ignore"` is passed for all
package managers (npm, pnpm, yarn, bun)
- All existing tests pass (909 total)