Add cloud testing workflow with updated production credentials

[Copilot]

Updates cloud ClickHouse instance environment variables to use production credentials with _PROD suffix per integrations team requirements.

Changes

• Created .github/workflows/run-tests-cloud.yml for cloud instance testing
  • Triggers on master push, workflow_dispatch, or PRs labeled tests:run-cloud
  • Uses updated secrets:
    • INTEGRATIONS_TEAM_TESTS_CLOUD_HOST_SMT_PROD
    • INTEGRATIONS_TEAM_TESTS_CLOUD_PASSWORD_SMT_PROD
    • INTEGRATIONS_TEAM_TESTS_CLOUD_JWT_DESERT_VM_43_PROD
  • Builds with OpenSSL support for SSL connections
  • Adapted from clickhouse-go pattern

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}