[Port] [2022.3] [SRPF] Fix an exception when delegate target is empty

.Net 8 and .Net Standard have a different behaviour for RuntimeHelpers.GetHashCode
In .Net 8 it's acceptable to pass null. https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.runtimehelpers.gethashcode?view=net-8.0
In Standard it's not. https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.runtimehelpers.gethashcode?view=netstandard-2.1

Author: svc-reach-platform-support

Packages/com.unity.render-pipelines.core/Runtime/Utilities/HashFNV1A32.cs

@@ -112,7 +112,7 @@ public void Append(Delegate del)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal static int GetFuncHashCode(Delegate del)
         {
-            return del.Method.GetHashCode() ^ RuntimeHelpers.GetHashCode(del.Target);
+            return del.Method.GetHashCode() ^ (del.Target != null ? RuntimeHelpers.GetHashCode(del.Target) : 0);
         }
 
         public int value => (int)m_Hash;