test: an invite's zone may be EDT or EST, and an unsent install counts from a recent backup (#6355)

The invite test asserted EDT for a time a day from now, so it failed from today:
a one-day link now ends after New York's clocks change on 1 November. It would
have stayed red until March.

The Home Assistant test used a fixed backup time, which put the unsent install
past its deadline at once.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/integration/test_homeassistant.py

@@ -9,6 +9,7 @@ import json
 import os
 import time
 import uuid
+from datetime import datetime, timezone
 from urllib.parse import parse_qs, urlparse
 
 import httpx
@@ -304,7 +305,8 @@ def test_an_install_that_couldnt_reach_home_assistant_is_asked_for_again(app):
         await _clean(app)
         await sched.poll(app, transport=ha.transport)
         await upd.start_update(app, ADDON, "someone", transport=ha.transport)
-        ha.backup_lands()
+        # Now, as the install's deadline counts from the backup while it is unsent.
+        ha.entities["sensor.backup_last_successful_automatic_backup"]["state"] = datetime.now(timezone.utc).isoformat()
         await upd.advance(app, transport=ha.transport)
         ha.down = True
         await upd.advance(app, transport=ha.transport)