fix: only set timeout for TTY

[mdonnalley]

Only set a timeout for a prompt if process.stdin.TTY is truthy

QA

1. checkout this branch and yarn build
2. yarn && yarn build in plugin-not-found directory
3. yarn link @oclif/core in plugin-not-found directory
4. sf plugins link --no-install in plugin-not-found directory
5. Test the following:

Standard misspelled command scenario. Prompt should timeout after 10 seconds.

❯ time sf verson
 ›   Warning: @oclif/plugin-not-found is a linked ESM module and cannot be auto-transpiled. Existing compiled source will be used
 ›   instead.
 ›   Warning: verson is not a sf command.
Did you mean version? [y/n]:

 ›   Error: Run sf help for a list of available commands.
sf verson  0.55s user 0.09s system 6% cpu 10.429 total

Piping answer to prompt. Should not wait for timeout.

❯ echo y | sf verson
 ›   Warning: @oclif/plugin-not-found is a linked ESM module and cannot be auto-transpiled. Existing compiled source will be used
 ›   instead.
 ›   Warning: verson is not a sf command.
Did you mean version? [y/n]: y
@salesforce/cli/2.28.6 darwin-arm64 node-v20.11.0

Redirecting stdin to /dev/null should exit immediately with 0 exit code

❯ sf verson </dev/null
 ›   Warning: @oclif/plugin-not-found is a linked ESM module and cannot be auto-transpiled. Existing compiled source will be used
 ›   instead.
 ›   Warning: verson is not a sf command.
Did you mean version? [y/n]: %

❯ echo $?
0

@W-15100925@

[iowillhoit]

Looks good. Tested locally and exit codes are correct