Improve login smoke tests

[markdboyd]

The current login smoke tests were based on the ones from Logsearch. Unfortunately, these do not work for testing successful login with the authentication proxy.

Instead, we will need some basic e2e tests using playwright to ensure that logging in works successfully

Acceptance Criteria

• Update login smoke tests to use Playwright to test login
  • Current tests: https://github.com/cloud-gov/deploy-logs-opensearch/blob/main/ci/smoke-tests-login.py
  • Example from proxy tests: https://github.com/cloud-gov/opensearch-dashboards-cf-auth-proxy/blob/main/e2e/test_setup.py#L11