Replace Ubuntu 18.04 Docker images with Ubuntu 22.04

[tkilias]

Update Ubuntu docker images (proposal: to 22.04). There are still some places using the 18.04 Ubuntu image, like:

• heath.sh
  • docker_check_pull:

    integration-test-docker-environment/scripts/health.sh

    Line 106 in a77a910

    details=$("docker" pull ubuntu:18.04 2>&1)

  • docker_check_connectivity:

    integration-test-docker-environment/scripts/health.sh

    Line 120 in a77a910

    details=$(docker run --rm ubuntu:18.04 bash -c ": >/dev/tcp/1.1.1.1/53")

• spawn_test_database.py
• test_analyze_image/Dockerfile
• test_test_container_reuse/tests/Dockerfile
• test_api_test_environment_docker_environment.py
• Update Docker image for start scripts and test test containers from Ubuntu 20.04 (EOL Apr 2025) to Ubuntu 22.04
• https://github.com/search?q=repo%3Aexasol%2Fintegration-test-docker-environment%20ubuntu&type=code
• github workflows ubuntu version should be pinned