Use tracing instead of log in collab and rpc crates

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

crates/collab/src/main.rs

@@ -44,7 +44,7 @@ impl AppState {
 #[tokio::main]
 async fn main() -> Result<()> {
     if let Err(error) = env::load_dotenv() {
-        log::error!(
+        eprintln!(
             "error loading .env.toml (this is expected in production): {}",
             error
         );