Remove debug message about pruning active leaves (#6440)

# Description

The debug message was added to identify a potential memory leak.
However, recent observations show that pruning works as expected.
Therefore, it is best to remove this line, as it generates quite
annoying logs.


## Integration

Doesn't affect downstream projects.

---------

Co-authored-by: GitHub Action <action@github.com>

polkadot/node/core/pvf/src/execute/queue.rs

@@ -305,8 +305,6 @@ impl Queue {
 		for hash in &update.deactivated {
 			let _ = self.active_leaves.remove(&hash);
 		}
-
-		gum::debug!(target: LOG_TARGET, size = ?self.active_leaves.len(), "Active leaves pruned");
 	}
 
 	fn insert_active_leaf(&mut self, update: ActiveLeavesUpdate, ancestors: Vec<Hash>) {

prdoc/pr_6440.prdoc

+title: Remove debug message about pruning active leaves
+doc:
+- audience: Node Dev
+  description: |-
+    Removed useless debug message
+crates:
+- name: polkadot-node-core-pvf
+  validate: false