refactor(tvix/cli/args): remove log-level argument

RUST_LOG allows for a more granular tracing configuration

Change-Id: Iea29fc2b154345eb7479dfd8bbea6abfd4716341
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12585
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>

tvix/cli/src/main.rs

@@ -53,7 +53,6 @@ fn main() {
     let args = Args::parse();
 
     let _ = tvix_tracing::TracingBuilder::default()
-        .level(args.log_level)
         .enable_progressbar()
         .build()
         .expect("unable to set up tracing subscriber");