BUG: Ensure launcher scripts installed from wheels are accessible

This commit addresses an issue where launcher scripts installed from wheels
were not correctly added to the PATH. Specifically, it updates the PATH for
both "Slicer" and "PythonSlicer" launcher settings in the build and install
tree. This adjustment ensures that convenience executables created after
installing wheels with specified entry-points such as "project.scripts" or
"project.gui-scripts" can be easily located and accessed within the project
environment.

SuperBuild/External_python.cmake

@@ -277,6 +277,14 @@ if((NOT DEFINED PYTHON_INCLUDE_DIR
   endif()
   mark_as_superbuild(PYTHON_VALGRIND_SUPPRESSIONS_FILE:FILEPATH)
 
+  #-----------------------------------------------------------------------------
+  # Directory where executable scripts associated with "project.scripts" or "project.gui-scripts"
+  # entry-points are generated
+  set(_scripts_subdir bin)
+  if(WIN32)
+    set(_scripts_subdir Scripts)
+  endif()
+
   #-----------------------------------------------------------------------------
   # Slicer Launcher setting specific to build tree
 
@@ -293,7 +301,10 @@ if((NOT DEFINED PYTHON_INCLUDE_DIR
     )
 
   # paths
-  set(${proj}_PATHS_LAUNCHER_BUILD ${python_DIR}/bin)
+  set(${proj}_PATHS_LAUNCHER_BUILD
+    ${python_DIR}/bin
+    ${python_DIR}/${_scripts_subdir}
+    )
   mark_as_superbuild(
     VARS ${proj}_PATHS_LAUNCHER_BUILD
     LABELS "PATHS_LAUNCHER_BUILD"
@@ -333,6 +344,15 @@ if((NOT DEFINED PYTHON_INCLUDE_DIR
       )
   endif()
 
+  # paths
+  set(${proj}_PATHS_LAUNCHER_INSTALLED
+    <APPLAUNCHER_SETTINGS_DIR>/../lib/Python/${_scripts_subdir}
+    )
+  mark_as_superbuild(
+    VARS ${proj}_PATHS_LAUNCHER_INSTALLED
+    LABELS "PATHS_LAUNCHER_INSTALLED"
+    )
+
   # pythonpath
   set(${proj}_PYTHONPATH_LAUNCHER_INSTALLED
     <APPLAUNCHER_SETTINGS_DIR>/../lib/Python/${PYTHON_STDLIB_SUBDIR}

SuperBuild/python_configure_python_launcher.cmake

@@ -79,6 +79,13 @@ endforeach()
 
 find_package(CTKAppLauncher REQUIRED)
 
+# Directory where executable scripts associated with "project.scripts" or "project.gui-scripts"
+# entry-points are generated.
+set(_scripts_subdir bin)
+if(WIN32)
+  set(_scripts_subdir Scripts)
+endif()
+
 #
 # Settings specific to the build tree.
 #
@@ -129,6 +136,7 @@ slicer_dll_directories.add()
 # PATHS
 set(PYTHONLAUNCHER_PATHS_BUILD
   <APPLAUNCHER_DIR>
+  <APPLAUNCHER_DIR>/../${_scripts_subdir}
   )
 
 # LIBRARY_PATHS
@@ -184,6 +192,7 @@ set(PYTHONHOME "<APPLAUNCHER_DIR>/../lib/Python")
 # PATHS
 set(PYTHONLAUNCHER_PATHS_INSTALLED
   <APPLAUNCHER_DIR>
+  <APPLAUNCHER_DIR>/../lib/Python/${_scripts_subdir}
   )
 
 # LIBRARY_PATHS