bpo-36941: Project file fixups for Windows ARM64 (GH-13477)

diff --git a/PCbuild/python.vcxproj b/PCbuild/python.vcxproj
index 919b79d..bd05146 100644
--- a/PCbuild/python.vcxproj
+++ b/PCbuild/python.vcxproj
@@ -55,7 +55,7 @@
     </ProjectConfiguration>
     <ProjectConfiguration Include="Release|ARM64">
       <Configuration>Release</Configuration>
-      <Platform>ARM</Platform>
+      <Platform>ARM64</Platform>
     </ProjectConfiguration>
     <ProjectConfiguration Include="Release|Win32">
       <Configuration>Release</Configuration>