Adds block production time in logs (#10205)

substrate/client/basic-authorship/src/basic_authorship.rs

@@ -462,8 +462,9 @@ where
 		});
 
 		info!(
-			"🎁 Prepared block for proposing at {} [hash: {:?}; parent_hash: {}; extrinsics ({}): [{}]]",
+			"🎁 Prepared block for proposing at {} ({} ms) [hash: {:?}; parent_hash: {}; extrinsics ({}): [{}]]",
 			block.header().number(),
+			block_timer.elapsed().as_millis(),
 			<Block as BlockT>::Hash::from(block.header().hash()),
 			block.header().parent_hash(),
 			block.extrinsics().len(),