[FIX] base: user.share recomputation

When saving the settings, we perform a `write` on the groups and implied
groups. This will trigger a recomputation of the fields `share` on
`res.users` and `partner_share` on `res.partner`.

On a database with many users, this can lead to a non-negligible time
spent in these methods.

opw-1830145

odoo/addons/base/res/res_config.py

@@ -531,12 +531,14 @@ class ResConfigSettings(models.TransientModel, ResConfigModuleInstallationMixin)
             IrValues.set_default(model, field, value)
 
         # group fields: modify group / implied groups
-        for name, groups, implied_group in classified['group']:
-            if self[name]:
-                groups.write({'implied_ids': [(4, implied_group.id)]})
-            else:
-                groups.write({'implied_ids': [(3, implied_group.id)]})
-                implied_group.write({'users': [(3, user.id) for user in groups.mapped('users')]})
+        with self.env.norecompute():
+            for name, groups, implied_group in classified['group']:
+                if self[name]:
+                    groups.write({'implied_ids': [(4, implied_group.id)]})
+                else:
+                    groups.write({'implied_ids': [(3, implied_group.id)]})
+                    implied_group.write({'users': [(3, user.id) for user in groups.mapped('users')]})
+        self.recompute()
 
         # other fields: execute all methods that start with 'set_'
         for method in dir(self):