Remove JsMVA source code

The JsMVA features were not functional for years, and therefore excluded
from ROOT 6.38 with commit 41f7ac4. Therefore, for ROOT 6.42,
it's appropriate to remove the sources for good.

Author: guitargeek

CMakeLists.txt

@@ -356,9 +356,6 @@ file(GLOB_RECURSE artifact_files RELATIVE ${CMAKE_SOURCE_DIR} etc/*)
 # Exclude the *.in files, just like in the install tree
 list(FILTER artifact_files EXCLUDE REGEX "\.(in)$")
 
-# Exclude etc/notebook/JsMVA
-list(FILTER artifact_files EXCLUDE REGEX "^etc/notebook/JsMVA/")
-
 foreach(artifact_file ${artifact_files})
   add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/${artifact_file}
     COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_SOURCE_DIR}/${artifact_file} ${CMAKE_BINARY_DIR}/${artifact_file}
@@ -530,7 +527,6 @@ install(
    PATTERN "*.pcm"
    PATTERN "modules.idx"
    PATTERN "JupyROOT" EXCLUDE
-   PATTERN "JsMVA" EXCLUDE
    PATTERN "python*" EXCLUDE
    PATTERN "cmake" EXCLUDE
    PATTERN "pkgconfig" EXCLUDE
@@ -637,7 +633,6 @@ if(NOT CMAKE_SOURCE_DIR STREQUAL CMAKE_INSTALL_PREFIX)
   endif()
   install(DIRECTORY etc/ DESTINATION ${CMAKE_INSTALL_SYSCONFDIR} USE_SOURCE_PERMISSIONS
                          ${DIR_PERMISSIONS}
-                         PATTERN "notebook/JsMVA" EXCLUDE
                          PATTERN "system.rootrc" EXCLUDE
                          PATTERN "root.mimes" EXCLUDE
                          PATTERN "*.in" EXCLUDE)

README/ReleaseNotes/v642/index.md

@@ -50,6 +50,7 @@ The following people have contributed to this new version:
 * The inclusion by external projects of Makefile templates contained within ROOT is deprecated in 6.42, a warning will be raised if you use them. These files will be removed in ROOT 7.
 * The conversion from Python set to **RooArgSet** is deprecated and won't work anymore in ROOT 6.44. The problem is that Python sets are unordered while RooArgSets are ordered, and this mismatch can lead to subtle problems later on. Prefer conversion from Python lists or tuples, which are ordered too.
 * The ROOT IO capability for the `TMVA::Experimental::SOFIE::RModel` has been removed. Users should not be encouraged to serialize models in experimental classes. For the serialization of ONNX models one can already use ONNX directly, and even serialize the ONNX bytes to a ROOT file if required.
+* The **JsMVA** feature for interactive TMVA training in Jupyter notebooks is now removed. It was not functional for years and was therefore already excluded from ROOT 6.38. This also removes the `TMVA::IPythonInteractive` class and the related interactive-training interfaces from the TMVA method and fitter classes, such as `MethodBase::ExitFromTraining()` or `FitterBase::SetIPythonInteractive()`.
 
 ## Python Interface
 

bindings/pyroot/pythonizations/python/CMakeLists.txt

@@ -89,12 +89,6 @@ if(tmva)
 endif()
 
 set(py_sources
-  #ROOT/JsMVA/DataLoader.py
-  #ROOT/JsMVA/Factory.py
-  #ROOT/JsMVA/JPyInterface.py
-  #ROOT/JsMVA/JsMVAMagic.py
-  #ROOT/JsMVA/OutputTransformer.py
-  #ROOT/JsMVA/__init__.py
   ROOT/_application.py
   ROOT/_asan.py
   ROOT/_facade.py