[LogsDB] [Subscription basic] [zscaler_zia] Failing test daily: system test: default in zscaler_zia.alerts

- Stack version: maximum of either the version used in PR builds or 8.17.0 (GA version for LogsDB index mode)
- LogsDB: enabled
- Subscription: basic
- Package: zscaler_zia
- Failing test: system test: default
- DataStream: alerts
- Owners:
- @elastic/security-service-integrations
- @elastic/sit-crest-contractors

Error:
```
could not setup service: could not boot up service using Docker Compose: running Docker Compose up command failed: exit status 18: Head "https://docker.elastic.co/v2/observability/stream/manifests/v0.20.0": dial tcp 34.56.16.77:443: i/o timeout
```

First build failed: https://buildkite.com/elastic/integrations/builds/49175

Start with the `zscaler_zia` package's `alerts` DataStream system test, specifically the `default` test, and reproduce the failure in a build with LogsDB enabled. Check whether Docker Compose can pull `observability/stream:v0.20.0` and determine whether the timeout is transient or reproducible. Done means the system test completes successfully with the service booted, or the infrastructure failure is documented for the owners.

Written by the indexing model from the issue text.