build: remove unused label from vcbuild.bat

Remove the :wix-not-found label and harmonize the spelling of "WiX".

PR-URL: https://github.com/nodejs/node/pull/26901
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

vcbuild.bat

@@ -239,7 +239,7 @@ if defined msi (
     goto msbuild-not-found
   )
   if not exist "%VCINSTALLDIR%\..\MSBuild\Microsoft\WiX" (
-    echo Failed to find the Wix Toolset Visual Studio 2017 Extension
+    echo Failed to find the WiX Toolset Visual Studio 2017 Extension
     goto msbuild-not-found
   )
 )
@@ -266,10 +266,6 @@ echo Try to run in a "Developer Command Prompt" or consult
 echo https://github.com/nodejs/node/blob/master/BUILDING.md#windows-1
 goto exit
 
-:wix-not-found
-echo Build skipped. To generate installer, you need to install Wix.
-goto install-doctools
-
 :msbuild-found
 
 set project_generated=