Revert "[FIX]base: fix domain of "user_id" field in res.partner"

This reverts commit a6c26aedf4c8043ac79b241acf6d69d1498f0acd.

closes odoo/odoo#68466

X-original-commit: 18281db9c918ff7b2b0c2fba841ffd8a141f046f
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

odoo/addons/base/models/res_partner.py

@@ -169,7 +169,7 @@ class Partner(models.Model):
 
     tz_offset = fields.Char(compute='_compute_tz_offset', string='Timezone offset', invisible=True)
     user_id = fields.Many2one('res.users', string='Salesperson',
-      help='The internal user in charge of this contact.', domain=lambda self: [('groups_id', 'in', self.env.ref('base.group_user').id)])
+      help='The internal user in charge of this contact.')
     vat = fields.Char(string='Tax ID', index=True, help="The Tax Identification Number. Complete it if the contact is subjected to government taxes. Used in some legal statements.")
     same_vat_partner_id = fields.Many2one('res.partner', string='Partner with same Tax ID', compute='_compute_same_vat_partner_id', store=False)
     bank_ids = fields.One2many('res.partner.bank', 'partner_id', string='Banks')