ITK nightly version update

This commit updates:
  (1) SHA used in CMakeLists.txt to checkout ITK sources
          (InsightSoftwareConsortium/ITK@73e883daba)
  (2) VERSION variable set in itkVersion.py

It was automatically generated by the script update_python_version.sh [1]

[1] https://github.com/InsightSoftwareConsortium/ITKPythonPackage/blob/74561b6/scripts/update_python_version.py

Author: kwrobot

CMakeLists.txt

@@ -90,7 +90,7 @@ if(ITKPythonPackage_SUPERBUILD)
   set(ITK_REPOSITORY "https://github.com/InsightSoftwareConsortium/ITK.git")
 
  # ITK nightly-master 2022-07-05
-  set(ITK_GIT_TAG "c44a7731f2")
+  set(ITK_GIT_TAG "73e883daba")
 
   #-----------------------------------------------------------------------------
   # A separate project is used to download ITK, so that it can reused

itkVersion.py

@@ -1,4 +1,4 @@
-VERSION = '5.3rc03.dev20220704+501.gc44a7731f2'
+VERSION = '5.3rc03.dev20220706+508.g73e883daba'
 
 def get_versions():
     """Returns versions for the ITK Python package.