Auth list tenants is not pageable

* Firebase SDK version: 9.8.0
* Firebase Product: auth

Fetching tenants with firebaseAuth.getTenantManager().listTenants(null) does not return a PageToken even though more pages exist. There is no possibility to page through all tenants.

```java
private List getAllTenants() {
ListTenantsPage listTenantsPage = null;
List allTenants = new ArrayList<>();
try {
do {
listTenantsPage = firebaseAuth.getTenantManager().listTenants(listTenantsPage == null ? null : listTenantsPage.getNextPageToken());
for (Tenant tenant : listTenantsPage.iterateAll()) {
allTenants.add(tenant);
}
log.info("Next page token: {}", listTenantsPage.getNextPageToken());
} while (listTenantsPage.hasNextPage());
} catch (FirebaseAuthException e) {
log.error("Could not list tenants", e);
}
log.info("Found {} tenants", allTenants.size());
return allTenants;
}
```

When viewing the tenants in the GCP Identity Platform, the same request is used with a page size of 2147483647. However, the admin sdk prevents requesting a page size over 100 (FirebaseTenantClient.MAX_LIST_TENANTS_RESULTS).

Please either remove the page size restriction in the sdk or fix pagination with page token of tenants

Start with FirebaseTenantClient.MAX_LIST_TENANTS_RESULTS and the TenantManager.listTenants call shown in the report. Run or inspect the existing ListTenantsPage pagination behavior, comparing it with the GCP Identity Platform request described. Done means tenants can be retrieved across all available pages without the SDK incorrectly preventing the required request.

索引モデルが issue の本文から書いたものです。