refactor: simplify ProofTaskMetrics default implementation

- Updated the ProofTaskMetrics struct to derive Default, removing the manual implementation of the default method.
- This change enhances code clarity and reduces boilerplate, while maintaining the same functionality.

crates/trie/parallel/src/proof_task_metrics.rs

@@ -5,7 +5,7 @@ use std::sync::{
 };
 
 /// Metrics for blinded node fetching by proof workers.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct ProofTaskMetrics {
     /// The actual metrics for blinded nodes.
     pub task_metrics: ProofTaskTrieMetrics,
@@ -19,18 +19,6 @@ pub struct ProofTaskMetrics {
     pub storage_nodes: Arc<AtomicU64>,
 }
 
-impl Default for ProofTaskMetrics {
-    fn default() -> Self {
-        Self {
-            task_metrics: ProofTaskTrieMetrics::default(),
-            storage_proofs: Arc::new(AtomicU64::new(0)),
-            account_proofs: Arc::new(AtomicU64::new(0)),
-            account_nodes: Arc::new(AtomicU64::new(0)),
-            storage_nodes: Arc::new(AtomicU64::new(0)),
-        }
-    }
-}
-
 impl ProofTaskMetrics {
     /// Record the blinded node counts into the histograms.
     pub fn record(&self) {