feat: Introduce NodeBuilder (#5869)

Co-authored-by: Dan Cline <6798349+Rjected@users.noreply.github.com>

crates/tracing/src/lib.rs

@@ -33,7 +33,8 @@ pub type BoxedLayer<S> = Box<dyn Layer<S> + Send + Sync>;
 
 /// Initializes a new [Subscriber] based on the given layers.
 pub fn init(layers: Vec<BoxedLayer<Registry>>) {
-    tracing_subscriber::registry().with(layers).init();
+    // To avoid panicking in tests, we silently fail if we cannot initialize the subscriber.
+    let _ = tracing_subscriber::registry().with(layers).try_init();
 }
 
 /// Builds a new tracing layer that writes to stdout.