Reverting fallback load handling

Author: fabiocav

src/WebJobs.Script/Description/DotNet/FunctionAssemblyLoadContext.cs

@@ -171,20 +171,6 @@ private Assembly LoadCore(AssemblyName assemblyName)
 
         protected override Assembly Load(AssemblyName assemblyName)
         {
-            if (_sharedContextAssembliesInFallbackLoad.ContainsKey(assemblyName.Name))
-            {
-                // Short circuit the probing logic as we're falling back to the original load
-                // context (from default), so just attempt to load the assembly:
-                var result = LoadCore(assemblyName);
-
-                if (result == null)
-                {
-                    throw new FileNotFoundException($"Could not load file or assembly '{assemblyName}'. The system cannot find the file specified.");
-                }
-
-                return result;
-            }
-
             // Try to load from deps references, if available
             if (TryLoadDepsDependency(assemblyName, out Assembly assembly))
             {