[WinRT] Adjust the installer for platform modulemaps

This is a companion to swiftlang/swift#84669.

Author: egorzhdan

platforms/Windows/platforms/windows/windows.wxs

@@ -3994,6 +3994,9 @@
       <Component DiskId="1">
         <File Source="$(SDKRoot)\usr\share\winsdk_shared.modulemap" />
       </Component>
+      <Component DiskId="1">
+        <File Source="$(SDKRoot)\usr\share\WinRT.modulemap" />
+      </Component>
       <Component DiskId="1">
         <File Source="$(SDKRoot)\usr\share\vcruntime.apinotes" />
       </Component>
@@ -4013,6 +4016,9 @@
       <Component>
         <File Source="$(ExperimentalSDKRoot)\usr\share\winsdk_shared.modulemap" />
       </Component>
+      <Component>
+        <File Source="$(ExperimentalSDKRoot)\usr\share\WinRT.modulemap" />
+      </Component>
       <Component>
         <File Source="$(ExperimentalSDKRoot)\usr\share\vcruntime.apinotes" />
       </Component>