[FIX] hr_holidays: fix traceback to add timezone

Currently, Traceback occurs when we do timezone filters in every one
report of time off because the timezone is non-stored compute field in
hr leave model.

So in this commit, get the timzone value based on compute field from
resource or timezone of the current company's calendar OR user's tz
and at last 'UTC'.

closes odoo/odoo#61910

Taskid: 2334866
X-original-commit: 05c373a99a6064f08fc9eb0662ab2ccdb1978cd7
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/hr_holidays/report/hr_leave_report_calendar.py

@@ -38,14 +38,20 @@ class LeaveReportCalendar(models.Model):
             hl.date_to AS stop_datetime,
             hl.employee_id AS employee_id,
             hl.state AS state,
-            em.company_id AS company_id
+            em.company_id AS company_id,
+            CASE
+                WHEN hl.holiday_type = 'employee' THEN rr.tz
+                ELSE %s
+            END AS tz
         FROM hr_leave hl
             LEFT JOIN hr_employee em
                 ON em.id = hl.employee_id
+            LEFT JOIN resource_resource rr
+                ON rr.id = em.resource_id
         WHERE 
             hl.state IN ('confirm', 'validate', 'validate1')
         ORDER BY id);
-        """)
+        """, [self.env.company.resource_calendar_id.tz or self.env.user.tz or 'UTC'])
 
     def _read(self, fields):
         res = super()._read(fields)