[FIX] auth_signup, website: make reset password multi website friendly

The "reset password" feature does not take into account
multi-website.

steps to reproduce:
- create a website A
- uncheck 'Shared Customer Accounts' on website A
- create a portal user user@example.com on website A
- create a website B
- uncheck 'Shared Customer Accounts' on website B
- create a portal user user@example.com on website B
- reset password for user@example.com on any website

before this commit:
An error is raised "No account found for this login"
(which is false, actually 2 accounts are found)

after this commit:
Only the user linked to the current website is properly
selected

opw-3551540

closes odoo/odoo#142110

X-original-commit: a2196253d6cf90dca3042a777703e0679f74f542
Signed-off-by: Romain Derie (rde) <rde@odoo.com>

odoo/addons/base/models/res_users.py

@@ -767,6 +767,10 @@ class Users(models.Model):
     def _get_login_domain(self, login):
         return [('login', '=', login)]
 
+    @api.model
+    def _get_email_domain(self, email):
+        return [('email', '=', email)]
+
     @api.model
     def _get_login_order(self):
         return self._order