sitemap.xml is empty after `cache:clear` in Multisite

[o1y]

Bug description

In a Multisite setup, the sitemap behaves inconsistently and becomes completely empty after clearing the cache.

How to reproduce

1. Have a multisite setup with a structured collection and localized entries
2. Run php please cache:clear
3. Open sitemap.xml

Result: /sitemap.xml is empty (0 entries).

Logs

Environment

Environment
Application Name: Statamic
Laravel Version: 12.53.0
PHP Version: 8.4.16
Composer Version: 2.8.10
Environment: local
Debug Mode: ENABLED
URL: statamic-seo-test.test
Maintenance Mode: OFF
Timezone: UTC
Locale: en

Cache
Config: NOT CACHED
Events: NOT CACHED
Routes: NOT CACHED
Views: CACHED

Drivers
Broadcasting: log
Cache: file
Database: sqlite
Logs: stack / single
Mail: log
Queue: sync
Session: file

Storage
public/storage: NOT LINKED

Statamic
Addons: 1
Sites: 2 (Statamic, German)
Stache Watcher: Enabled (auto)
Static Caching: Disabled
Version: 6.4.1 PRO

Statamic Addons
statamic/seo-pro: 7.1.1

Additional details

My PR statamic/cms#14031 revealed this bug for single-site setups, although the issue already existed before.

Another reproduction:

php please cache:clear
curl -s http://statamic-seo-test.test/sitemap.xml
php please tinker --execute="dump(Statamic\Facades\Entry::query()->whereNotNull('uri')->count());"

So when using ->whereNotNull('uri') all entries have null URIs (0 results).

Without the curl -s http://statamic-seo-test.test/sitemap.xml you'd get a correct count.