Remove FusionAssemblyIdentity and GlobalAssemblyCache as they are not used (PowerShell#18334)

Author: iSazonov

src/System.Management.Automation/engine/parser/Compiler.cs

@@ -2804,12 +2804,6 @@ private static Assembly LoadAssembly(string assemblyName, string scriptFileName)
                     assemblyFileName = Path.GetDirectoryName(scriptFileName) + "\\" + assemblyFileName;
                 }
 
-#if !CORECLR
-                if (!File.Exists(assemblyFileName))
-                {
-                    Microsoft.CodeAnalysis.GlobalAssemblyCache.ResolvePartialName(assemblyName, out assemblyFileName);
-                }
-#endif
                 if (File.Exists(assemblyFileName))
                 {
                     assembly = Assembly.LoadFrom(assemblyFileName);