[REV] website_sale: stop handling exclusions in /shop

Commit 91d0e9c6 made sure that excluded
combination did not appear in /shop search results, but it significantly
slowed down searches, even in databases without exclusions.

Since the excluded combinations cannot be added to the cart (and the
original feedback did not come from an effective ticket), we believe
the gain is not worth the cost.

This commit reverts that change.

Task-3326948

closes odoo/odoo#125187

Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>