[perf] Use TryGetValue for net module handler resolution

[Xekep]

This path runs for every net module packet.

This patch replaces a double dictionary lookup (ContainsKey + indexer) with a single TryGetValue lookup.

Behavior stays the same; it is only a small hot-path cleanup.

[greptile-apps]

Greptile Summary

This PR optimizes the net module packet handler by replacing a double dictionary lookup with a single TryGetValue call. The change is functionally equivalent but more efficient.

• Replaced ContainsKey + indexer pattern with TryGetValue in OnReceive method
• Reduces dictionary lookups from 2 to 1 for every net module packet processed
• Follows idiomatic C# best practices for dictionary access
• No behavioral changes, purely a performance optimization

Confidence Score: 5/5

• This PR is safe to merge with no risk
• The change is a straightforward performance optimization with no behavioral changes. The TryGetValue pattern is functionally identical to ContainsKey + indexer but more efficient. The code is simple, well-understood, and the optimization is a common C# best practice.
• No files require special attention

Important Files Changed

Filename	Overview
TShockAPI/Handlers/NetModules/NetModulePacketHandler.cs	Optimized dictionary lookup from ContainsKey+indexer to TryGetValue, reducing from 2 to 1 lookup in hot path

_{Last reviewed commit: 4ba2f1b}