[FIX] web: Many 2 One external link was invisible

Current behavior:
If you activate the packaging options of the inventory
tab. The external link of the packaging type in the inventory tab of a
product is invisible.

Steps to reproduce:
- Have inventory module installed
- Activate the packages & product's packaging options
- Go on a product page and then go in the inventory tab
- Add a line in the packaging tree view
- There should be an exteral link next to the packaging type after you
  selected one
- The external link is invisible

Note: similar issue was also present in the Document's workflow rules.

opw-2749832

closes odoo/odoo#87305

X-original-commit: 57a92e6a1178e3bd9d9f8995388cdc67a354c585
Signed-off-by: Christophe Monniez (moc) <moc@odoo.com>
Signed-off-by: Engels Robin (roen) <roen@odoo.com>

addons/web/static/src/legacy/scss/form_view.scss

@@ -594,7 +594,7 @@ $o-form-label-margin-right: 0px;
         }
 
         @include media-breakpoint-up(sm) {
-            :not(.o_row):not(.o_data_cell) > .o_field_widget,
+            :not(.o_row):not(.o_data_cell) > .o_field_widget > * >,
             .o_row > .o_field_widget:last-child { // Note: this does not take care
                                                 // of an invisible last-child but
                                                 // it does not really matter