Ensure that usernames, user ids, and client ids match in random collaboration test

This makes the logs easier to interpret

crates/collab/src/db.rs

@@ -2117,7 +2117,7 @@ pub mod tests {
             Self {
                 background,
                 users: Default::default(),
-                next_user_id: Mutex::new(1),
+                next_user_id: Mutex::new(0),
                 projects: Default::default(),
                 worktree_extensions: Default::default(),
                 next_project_id: Mutex::new(1),