Remove hctgettaef.py, fix link to WDK download page (microsoft#7888)

hctgettaef.py downloaded a very old, unsupported version of TAEF. We
should be guiding people to download official supported versions, such
as the one that you get from the Windows Driver Kit.

hctdeploytest.cmd was using hctgettaef.py, but as I can't find any
references to it anywhere I'm going to assume it is unused and will
remove it rather than try to maintain it.

Closes microsoft#7881

Author: damyanp

utils/hct/hctdeploytest.cmd

@@ -167,8 +167,7 @@ if exist "%HLSL_SRC_DIR%\external\taef\build\Binaries\amd64\TE.exe" set path=%pa
 where te.exe 1>nul 2>nul
 if errorlevel 1 (
   echo Unable to find TAEF te.exe on path - you will have to add this before running tests.
-  echo WDK includes TAEF and is available from https://msdn.microsoft.com/en-us/windows/hardware/dn913721.aspx
-  echo Alternatively, consider a project-local install by running %HLSL_SRC_DIR%\utils\hct\hctgettaef.py
+  echo WDK includes TAEF and is available from https://learn.microsoft.com/en-us/windows-hardware/drivers/download-the-wdk
   echo Please see the README.md instructions in the project root.
   exit /b 1
 )