BUG: Update PythonQt to fix intallation of light-the-torch in Slicer

This commit fixes the following error reported when trying to install
light-the-torch in Slicer:

  AttributeError: 'PythonQtStdInRedirect' object has no attribute 'isatty'

See Slicer/Slicer#5705

List of changes:

$ git shortlog dafdb72..c306140 --no-merges
Andras Lasso (1):
      [Backport] Add isatty() method to PythonQtStdIn class

CMakeExternals/PythonQt.cmake

@@ -82,7 +82,7 @@ if(NOT DEFINED PYTHONQT_INSTALL_DIR)
   ctkFunctionExtractOptimizedLibrary(PYTHON_LIBRARIES PYTHON_LIBRARY)
 
   if (CTK_QT_VERSION VERSION_GREATER "4")
-    set(revision_tag dafdb7255b82163329672edebba4f267958c7376) # patched-10
+    set(revision_tag c306140442feb6e76d4bae672c48cd7f11d9b0cd) # patched-9
   else()
     set(revision_tag 90c08fb0d523622d2de9e7a91f4ef116a66a8801) # patched-5
   endif()