utils: T9185: ask_yes_no() fails fast on non-tty instead of silent default

jestabro (and dmbaturin previously, on #5362) pointed out that silently
returning `default` on a non-TTY stdin still violates ask_yes_no()'s
interactive-only contract, even though it stops the CPU-spin. Per T9185,
sageframe's original incident confirms why: a caller that forgets an
explicit non-interactive guard gets no error and no visible hang, just
a process quietly pegging a core for days.

Raise EOFError immediately instead, so a missing guard fails loudly and
fast rather than either spinning or silently succeeding. Existing callers
that are meant to run non-interactively already check no_prompt/-y before
calling this (config_mgmt.py, backend.py) and are unaffected.

0 files changed, 0 insertions, 0 deletions