Replace Enumerable.Range().Select() with direct for loops to reduce allocations

[0xLogicalx]

Replaces LINQ-based task collection initialization with direct for loops in performance-critical code paths, eliminating unnecessary intermediate allocations.

[Copilot]

Pull request overview

This PR optimizes performance-critical code paths by replacing LINQ-based collection initialization with direct for loops, eliminating unnecessary intermediate allocations from Enumerable.Range().Select() chains.

Key Changes:

• Replaced LINQ-based task collection creation with direct for loops in two high-throughput components
• Properly handled loop variable capture in closures to avoid common pitfalls
• Removed unused using System.Linq directive where applicable

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Nethermind/Nethermind.Trie/BatchedTrieVisitor.cs	Replaced LINQ chain with direct for loop for task creation in batched trie visiting; removed unused using System.Linq directive
src/Nethermind/Nethermind.Network/PeerManager.cs	Replaced LINQ chain with direct for loop for worker task creation; correctly captured loop variable to avoid closure issues

[LukaszRozmej]

we can probably avoid closure with something like:

for (int idx = 0; idx < _outgoingConnectParallelism; idx++)
{
    tasks.Add(RunWorker(idx));
}

async Task RunWorker(int workerIdx)
{
    await foreach (Peer peer in taskChannel.Reader.ReadAllAsync(_cancellationTokenSource.Token))
    {
        try
        {
            await SetupOutgoingPeerConnection(peer);
        }
        catch (TaskCanceledException)
        {
            if (_logger.IsDebug) _logger.Debug($"Connect worker {workerIdx} cancelled");
            break;
        }
        catch (Exception e)
        {
            if (_logger.IsError) _logger.Error($"Error setting up connection to {peer}, {e}");
        }
    }
    if (_logger.IsDebug) _logger.Debug($"Connect worker {workerIdx} completed");
}

[0xLogicalx]

Thanks for the suggestion! I switched the loop to call a local RunWorker(int workerIdx) helper so each worker receives its own index instead of capturing the loop variable. This removes the closure while keeping the behavior the same.

[LukaszRozmej]

Probably whitespace is off