kill-buffer without asking for confirmation

[Peter Münster]

Hi,

When a buffer is modified, kill-buffer normally asks for confirmation
("Buffer modified; kill anyway?"). How can I avoid this confirmation
please?

This worked with version 28.X:

(defun some-function-called-by-timer ()
  "Send email to user."
  (compose-mail user-mail-address "bla")
  (insert "bla")
  (funcall send-mail-function)
  (cl-letf (((symbol-function 'yes-or-no-p) (lambda (_) t)))
    (kill-buffer)))

But unfortunately, it doesn't work any more with the latest 29.0.50.

TIA for any help,
-- 
           Peter