Use JSON logs during Antithesis runs

[StephenButtolph]

Why this should be merged

Currently the antithesis tests perform string matching rather than looking at log levels.

How this works

Sets the log format to json.

How this was tested

Manually:

avalanche-node-1          | {"level":"trace","timestamp":"2024-11-21T19:39:31.316Z","logger":"P Chain","caller":"snowman/topological.go:594","msg":"accepting block","blkID":"RQSTTsQ9WAurX8M8fiDt6injR3GtiUETEDjHyDLT7L9uhAYBc","height":1,"timestamp":"2024-11-21T19:39:31.000Z"}

The logs for the nodes (not the workload) are now json 🥳

Need to be documented in RELEASES.md?

No.

[ARR4N]

Please add tests