[FIX] project: fix avatars alignment in subtasks dropdown in kanban view

Before this commit, avatars images were not aligned correctly

NB: The bug is only present in Firefox and pre v15.4 Safari because
these browsers don't support `:has` CSS selector. This selector is used
to set a `display: flex` on `.o_field_many2many_avatar_user` if it has
no `.o_tags_input` child in `many2many_avatar_user_field.scss`

task-3422356
part of task-3326263

closes odoo/odoo#129129

X-original-commit: fedf405aa821cf57b566c7992b0b14ad331bf80f
Signed-off-by: Pierre Paridans (app) <app@odoo.com>

addons/project/static/src/components/subtask_kanban_list/subtask_kanban_list.xml

@@ -20,7 +20,7 @@
                            t-esc="data.record.data.display_name"
                            t-on-click.prevent="() => this.goToSubtask(data.record.resId)"/>
                         <Field
-                            class="`subtask_user_widget_col justify-content-end align-items-center ${['1_done', '1_canceled'].includes(data.record.data.state) ? 'opacity-50' : ''}`"
+                            class="`subtask_user_widget_col d-inline-flex justify-content-end align-items-center me-1 ${['1_done', '1_canceled'].includes(data.record.data.state) ? 'opacity-50' : ''}`"
                             name="'user_ids'"
                             record="data.record"
                             fieldInfo="data.record.activeFields.user_ids"