Testcontainers Cloud doesn't depend on the local Docker installation running or being available.
If you'd like to check how Testcontainers-based tests work without local Docker running, stop Docker and rerun your test.
❕Note that Testcontainers Cloud is not a generic Docker replacement, and you might rely on Docker for other tasks for example using docker CLI to build images.
On Mac: Run osascript -e 'quit app "Docker"' to stop Docker.
On Windows: Quit the Docker Desktop application.
On Linux: Depending on the exact Linux distribution the command might be different. For example, on OracleLinux it's: systemctl restart docker.