Fix Google Calendar scheduling over Focus Time and Out of Office events (#50605)

<!-- Add the related story/sub-task/bug number, like Resolves #123, or
remove if NA -->
**Related issue:** Resolves
https://github.com/fleetdm/fleet/issues/50548

Fleet's calendar integration was scheduling maintenance events over
users' **Focus Time** and **Out of Office** blocks, even when those were
marked Busy.

The root cause is the event query in `ListEvents`
(ee/server/calendar/google_calendar.go), which only requested
`"default"` event types — so `focusTime` and `outOfOffice` events were
never returned and never considered during conflict detection.

## Change
Added the blocking event types to the query:

```go
EventTypes("default", "focusTime", "outOfOffice").
```

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.

---------

Co-authored-by: Lucas Manuel Rodriguez <lucas@fleetdm.com>

changes/50548-calendar-focus-time-out-of-office.md

@@ -0,0 +1 @@
+- Fixed the Google Calendar integration scheduling maintenance events over users' Focus Time and Out of office blocks.

ee/server/calendar/google_calendar.go

@@ -197,7 +197,7 @@ func (lowLevelAPI *GoogleCalendarLowLevelAPI) ListEvents(timeMin, timeMax string
 			}
 			// Default maximum number of events returned is 250, which should be sufficient for most calendars.
 			return lowLevelAPI.service.Events.List(calendarID).
-				EventTypes("default").
+				EventTypes("default", "focusTime", "outOfOffice").
 				OrderBy("startTime").
 				SingleEvents(true).
 				TimeMin(timeMin).