[Minor nit] toolchain install missing download detials

Attempting to install the toolchain on a very slow (KB/s) hangs on Extracting... but I believe that message is printed too early, while the download is progressing still:

cargo-wasix/src/toolchain.rs

Lines 602 to 612 in 07d5637

    
           // Download and extract sysroot. 
        
           eprintln!( 
        
               "Downloading sysroot from url '{}'...", 
        
               &sysroot_asset.browser_download_url 
        
           ); 
        
           let res = client 
        
               .get(&sysroot_asset.browser_download_url) 
        
               .send()? 
        
               .error_for_status()?; 
        
           eprintln!("Extracting...");

Some minimal progress bar would be great, but at least ensuring that it is clear what is blocking the install step-wise would be a very nice fix to have.

	// Download and extract sysroot.
	eprintln!(
	"Downloading sysroot from url '{}'...",
	&sysroot_asset.browser_download_url
	);
	let res = client
	.get(&sysroot_asset.browser_download_url)
	.send()?
	.error_for_status()?;

	eprintln!("Extracting...");