Default beacon/execution services are able to reach out by default.

[0xTylerHolmes]

Issue

By default, when running local experiments, the beacon and execution services are allowed to connect to external networks.

Risks

1. While the risk of actual network interference is currently low (due to differing genesis hashes), users may not be aware that a locally tested network could still reach out to other networks.
2. This also adds additional noise to some of the clients logs causing confusion during repro/RCA-ing that occurs post experiment.

Plausible Solutions

1. Restrict the beacon/execution services/containers to only use the network provided by Kurtosis. This would eliminate unintentional external connections and clearly communicate to users that testing is isolated by default.
2. Use the beacon/execution launchers to restrict the networks via CL args to the services themselves.