Simplify time zone setting in tests (#68330)

* Simplify timezone setting in tests

* Fix typo

* Adjust caldav tests

* Adjust input_datetime tests

* Adjust time_date tests

* Adjust tod tests

* Adjust helper tests

* Adjust recorder tests

* Adjust risco tests

* Adjust aemet tests

* Adjust flux tests

* Adjust forecast_solar tests

* Revert unnecessary change in forecast_solar test

* Adjust climacell tests

* Adjust google tests

* Adjust sensor tests

* Adjust sonarr tests

* Adjust template tests

* Adjust zodiac tests

Co-authored-by: Martin Hjelmare <marhje52@gmail.com>

tests/conftest.py

@@ -29,7 +29,7 @@ from homeassistant.components.websocket_api.http import URL
 from homeassistant.const import ATTR_NOW, EVENT_TIME_CHANGED, HASSIO_USER_NAME
 from homeassistant.helpers import config_entry_oauth2_flow, event
 from homeassistant.setup import async_setup_component
-from homeassistant.util import location
+from homeassistant.util import dt as dt_util, location
 
 from tests.ignore_uncaught_exceptions import IGNORE_UNCAUGHT_EXCEPTIONS
 
@@ -249,6 +249,8 @@ def load_registries():
 def hass(loop, load_registries, hass_storage, request):
     """Fixture to provide a test instance of Home Assistant."""
 
+    orig_tz = dt_util.DEFAULT_TIME_ZONE
+
     def exc_handle(loop, context):
         """Handle exceptions by rethrowing them, which will fail the test."""
         # Most of these contexts will contain an exception, but not all.
@@ -273,6 +275,10 @@ def hass(loop, load_registries, hass_storage, request):
     yield hass
 
     loop.run_until_complete(hass.async_stop(force=True))
+
+    # Restore timezone, it is set when creating the hass object
+    dt_util.DEFAULT_TIME_ZONE = orig_tz
+
     for ex in exceptions:
         if (
             request.module.__name__,