[windows] add _CompilerSwiftIfConfig dependency to the swift-syntax installer step

swiftlang/swift#75014 added the new dependency, that the swift compiler depends on, and thus we need to make sure that this DLL is installed

Author: hyp

platforms/Windows/bld/bld.wxs

@@ -387,6 +387,9 @@
       <Component>
         <File Source="$(TOOLCHAIN_ROOT)\usr\bin\_CompilerSwiftIDEUtils.dll" />
       </Component>
+      <Component>
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\_CompilerSwiftIfConfig.dll" />
+      </Component>
       <Component>
         <File Source="$(TOOLCHAIN_ROOT)\usr\bin\_CompilerSwiftOperators.dll" />
       </Component>