[FIX] web: StateSelectionField on list view

Even if the `StateSelectionField` is readonly we doesn't want visual
difference and we remove the `disabled` class.
This behavior is the same as in 15.

We also remove `btn-link` as it's not appear as a link and we had to set
`p-0` to avoid the growing of the cell.

Steps to reproduce:

> Open the helpdesk app
> Click on VIP Support tickets
> Go to the list view
> Add kanban_state column => visual bug

closes odoo/odoo#102504

X-original-commit: 26d6942ed1b0c328d94e7dfd5e50c18a68c8c2f3
Signed-off-by: Pierre Paridans (app) <app@odoo.com>
Signed-off-by: Romain Estievenart (res) <res@odoo.com>

addons/web/static/src/views/fields/state_selection/state_selection_field.xml

@@ -3,7 +3,7 @@
 
     <t t-name="web.StateSelectionField" owl="1">
         <t t-if="isReadonly">
-            <button class="d-flex align-items-center btn btn-link disabled">
+            <button class="d-flex align-items-center btn fw-normal p-0">
                 <span t-attf-class="o_status {{ statusColor(currentValue) }} "/>
                 <span t-if="showLabel" class="o_status_label ms-1" t-esc="label"/>
             </button>

addons/web/static/tests/views/fields/state_selection_field_tests.js

@@ -188,7 +188,6 @@ QUnit.module("Fields", (hooks) => {
         });
 
         assert.hasClass(target.querySelector(".o_field_state_selection"), "o_readonly_modifier");
-        assert.hasClass(target.querySelector(".o_field_state_selection button"), "disabled");
         assert.isNotVisible(target.querySelector(".dropdown-menu"));
         await click(target, ".o_field_state_selection span.o_status");
         assert.isNotVisible(target.querySelector(".dropdown-menu"));