How to properly unmap TAB in Quail translation keymap?

["Göktuğ Kayaalp" <self@gkayaalp.com>]

Hello,

I wish Quail to not show completions buffer when I hit TAB. It is almost
always accidental. But so far I haven’t been able to force Quail to let
go of TAB. My current relevant configuration:

;; Use C-<tab> to view quail completions
(define-key quail-translation-keymap [tab] nil)
(define-key quail-translation-keymap [C-tab] #'quail-completion)

which appears to be ineffective.

I use Quail all the time and this is the bane of my existence, and so
far the only real solution has been to use display buffer customisations
to hide the Quail buffer, which is suboptimal, as sometimes I /do/ want
it.

        -Göktuğ.