[FIX] tests: remove duplicate tests

The tests introduced in commit 4265026ee2
are replaced and optimized by the tests introduced in commit
cb4266787b

odoo/addons/base/tests/test_ir_actions.py

@@ -271,48 +271,6 @@ class TestCustomFields(common.TransactionCase):
         with self.assertRaises(ValidationError):
             self.create_field('foo')
 
-    def test_create_custom_o2m(self):
-        """ try creating a custom o2m and then deleting its m2o inverse """
-        model = self.env['ir.model'].search([('model', '=', self.MODEL)])
-        comodel = self.env['ir.model'].search([('model', '=', self.COMODEL)])
-
-        m2o_field = self.env['ir.model.fields'].create({
-            'model_id': comodel.id,
-            'name': 'x_my_m2o',
-            'field_description': 'my_m2o',
-            'ttype': 'many2one',
-            'relation': self.MODEL,
-        })
-
-        o2m_field = self.env['ir.model.fields'].create({
-            'model_id': model.id,
-            'name': 'x_my_o2m',
-            'field_description': 'my_o2m',
-            'ttype': 'one2many',
-            'relation': self.COMODEL,
-            'relation_field': m2o_field.name,
-        })
-
-        m2o_field.unlink()
-        self.assertFalse(o2m_field.exists())
-
-    def test_create_custom_related(self):
-        """ try creating a custom related then deleting its inverse """
-        comodel = self.env['ir.model'].search([('model', '=', self.COMODEL)])
-
-        field = self.create_field('x_my_char')
-
-        related_field = self.env['ir.model.fields'].create({
-            'model_id': comodel.id,
-            'name': 'x_oh_boy',
-            'field_description': 'x_oh_boy',
-            'ttype': 'char',
-            'related': 'partner_id.x_my_char',
-        })
-
-        field.unlink()
-        self.assertFalse(related_field.exists())
-
     def test_rename_custom(self):
         """ custom field names must be start with 'x_' """
         field = self.create_field('x_foo')