feat(tvix/tracing): optional progressbar

Disable the progressbar on default and provide a interface for
optionally enabling the progressbar.

Change-Id: I0e31b1957e80cf64a8dcf65c6ceb3713975b8220
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11861
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: Simon Hauser <simon.hauser@helsinki-systems.de>

tvix/store/src/bin/tvix-store.rs

@@ -506,7 +506,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     let tracing_handle = {
         let mut builder = tvix_tracing::TracingBuilder::default();
-        builder = builder.level(cli.log_level);
+        builder = builder.level(cli.log_level).enable_progressbar();
         #[cfg(feature = "otlp")]
         {
             if cli.otlp {