fix: silence all logging/tracing in tests

[emlautarom1]

Several tests utilize the run functions exposed by the CLI commands, yet some of these functions initialize the pluto_tracing module, resulting in logs cluttering stdout when running the tests (cargo test). For example:

pluto/crates/cli/src/commands/test/infra.rs

Lines 552 to 562 in ae0f152

	pub async fn run(
	args: TestInfraArgs,
	writer: &mut dyn Write,
	ct: CancellationToken,
	) -> Result<TestCategoryResult> {
	pluto_tracing::init(
	&pluto_tracing::TracingConfig::builder()
	.with_default_console()
	.build(),
	)
	.expect("Failed to initialize tracing");

This PR addresses this issue, ensuring that the pluto_tracing module is initialized only in main for which we don't have tests (and we don't intend to have either).