You can override `mshtml` to prevent wine from installing gecko.
WINEDLLOVERRIDES=mshtml=d wine somewineapp
To prevent both mono and gecko:
WINEDLLOVERRIDES=mscoree=d;mshtml=d wine somewineapp
And to keep all other possibly existing `WINEDLLOVERRIDES`:
WINEDLLOVERRIDES=mscoree=d;mshtml=d;$WINEDLLOVERRIDES wine somewineapp
See also:
* <
* What can I remove from a standard Wine wineprefix/bottle/configuration?