[FIX] hr_attendance: fix attendance check in/out layout issue when having no employee

When user is not linked to any employee and get try to check in/out then user
gets white screen. Instead correctly displays a warning message telling
the user should have an employee.

Screeshot: https://drive.google.com/file/d/1cX1NtCcELeTYgr0kK5cW4i5etyHtezAV/view

This commit is related to task ID 1841522. Closes PR #25230.

addons/hr_attendance/static/src/js/my_attendances.js

@@ -25,11 +25,7 @@ var MyAttendances = AbstractAction.extend({
                 args: [[['user_id', '=', this.getSession().uid]], ['attendance_state', 'name']],
             })
             .then(function (res) {
-                if (_.isEmpty(res) ) {
-                    self.$('.o_hr_attendance_employee').append(_t("Error : Could not find employee linked to user"));
-                    return;
-                }
-                self.employee = res[0];
+                self.employee = res.length && res[0];
                 self.$el.html(QWeb.render("HrAttendanceMyMainMenu", {widget: self}));
             });
 

addons/hr_attendance/static/src/xml/attendance.xml

@@ -47,7 +47,7 @@
                     <h3 class="mt0 mb0 text-muted">Click to <b t-if="checked_in">check out</b><b t-if="!checked_in">check in</b></h3>
                 </t>
                 <t t-else="">
-                    Error : Could not find employee linked to user.
+                    Warning : Your user should be linked to an employee to use attendance. Please contact your administrator.
                 </t>
             </div>
         </div>