[FIX] base: unique module name declared twice

before this commit, there was 2 unique indexes on module name
after this commit, only 1 unique index remains (the one declared in base/ir_module.py) to keep the error message

closes odoo/odoo#85116

Signed-off-by: Raphael Collet <rco@odoo.com>

odoo/addons/base/data/base_data.sql

@@ -67,7 +67,6 @@ CREATE TABLE ir_module_module (
     to_buy boolean default False,
     primary key(id)
 );
-ALTER TABLE ir_module_module add constraint name_uniq unique (name);
 
 CREATE TABLE ir_module_module_dependency (
     id serial NOT NULL,