Manipulating keymaps

Greetings,

After eventually upgrading  from Emacs 28.2 to 30.2  I have problems de-
fining personal key bindings  which are intended for being active in ALL
keymaps.  In 28.2 I simply used something like

  (global-set-key (kbd "C-x M-y") 'function)

to globally define  all my personal key bindings.   But apart from func-
tion "global-set-key"  meanwhile being deprecated  this function as well
as its successor "keymap-global-set"  no longer override key bindings in
more specific keymaps, as is pointed out when running

   C-h f keymap-global-set

   ...
   Note that if KEY has a local binding in the current buffer, that
   local binding will continue to shadow any global binding that you
   make with this function.
   ...

So how can I define key bindings which override all built-in keymaps?

Sincerely,
  Rainer