fix: use local spawn on wasm targets

[HoKim98]

Which issue does this PR close?

Closes #.

Rationale for this change

The BoxedStaticFuture<T> is typed as:

/// BoxedStaticFuture is the type alias of [`futures::future::BoxFuture`].
#[cfg(not(target_arch = "wasm32"))]
pub type BoxedStaticFuture<T> = futures::future::BoxFuture<'static, T>;
#[cfg(target_arch = "wasm32")]
/// BoxedStaticFuture is the type alias of [`futures::future::LocalBoxFuture`].
pub type BoxedStaticFuture<T> = futures::future::LocalBoxFuture<'static, T>;

But the current tokio executor only calls the Sendable spawn function like:

/// Executor that uses the [`tokio::task::spawn`] to execute futures.
#[derive(Default)]
pub struct TokioExecutor {}

impl Execute for TokioExecutor {
    /// Tokio's JoinHandle has its own `abort` support, so dropping handle won't cancel the task.
    fn execute(&self, f: BoxedStaticFuture<()>) {
        let _handle = tokio::task::spawn(f)
    }
}

So this PR just fixes the problem like:

/// Executor that uses the [`tokio::task::spawn`] to execute futures.
#[derive(Default)]
pub struct TokioExecutor {}

impl Execute for TokioExecutor {
    /// Tokio's JoinHandle has its own `abort` support, so dropping handle won't cancel the task.
    fn execute(&self, f: BoxedStaticFuture<()>) {
+        #[cfg(not(target_arch = "wasm32"))]
        let _handle = tokio::task::spawn(f);
+
+        #[cfg(target_arch = "wasm32")]
+        let _handle = tokio::task::spawn_local(f);
    }
}

And, there are also some clippy mutes on (WASM) targets.

What changes are included in this PR?

Are there any user-facing changes?

NONE