cleanup: remove unnecessary comments

[SeaRoll]

No description provided.

[Copilot]

Pull request overview

This PR removes unnecessary comments from src/lib.rs to improve code readability and reduce clutter. The comments being removed are either overly explanatory for straightforward code or provide information that is already clear from the code itself.

Changes:

• Removed section separator comment for Error and Waker definitions
• Removed redundant documentation and inline comments from the spawn_task! macro
• Removed verbose explanatory comments from test helper functions and test setup

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The removal of documentation for the Task type alias leaves it without explanation. This type alias involves complex Rust concepts (Pin, trait objects, lifetime parameters) that would benefit from documentation explaining its purpose as a pinned future for the task queue.

Suggested change

	/// A pinned, dynamically-dispatched future representing a single task.
	///
	/// This alias is the internal task type stored in the [`Spawner`]’s queue and
	/// wrapped by [`TaskHandle`]. It is a `Pin`ned mutable reference to a trait
	/// object implementing [`core::future::Future`] with `Output = ()`, and is
	/// required to be both `Send` and `Sync` so it can be safely scheduled.
	///
	/// The lifetime parameter `'a` is the lifetime of the underlying borrowed
	/// future. Using `Pin` ensures that the future will not be moved in memory
	/// while it is being polled by the runtime.