[PyROOT] Drop support for from ROOT import *

Wild card imports like `from ROOT import *` stopped working with Python
3.11 given some changes in the CPython API.

For that reason, upstream `cppyy` also dropped support for lazy lookups,
which was the feature that enabled wildcard imports:
wlav/CPyCppyy@64fd890#diff-6160c0eb004dabeedaeb58d804a7ecd3e563d9379e9e7af39623fd38d0bc6a37R352

This commit suggests to document `from ROOT import *` officially as
unsupported and remove the corresponding code path in the ROOT facade.

Closes #7669.

README/ReleaseNotes/v632/index.md

@@ -44,6 +44,7 @@ The following people have contributed to this new version:
 - Some redundant **RooDataSet** constructors are deprecated and will be removed in ROOT 6.34.
   Please use the RooDataSet constructors that take RooFit command arguments instead
 - ROOT does not longer support Python 2. The minimum required Python version to build ROOT is 3.8.
+- Support for wildcard imports like `from ROOT import *` is dropped from PyROOT
 
 ## Core Libraries
 

bindings/pyroot/pythonizations/python/ROOT/_facade.py

@@ -145,22 +145,6 @@ def AddressOf(self, obj):
         # Create a buffer (LowLevelView) from address
         return cppyy.ll.cast[out_type](addr)
 
-    def _handle_import_all(self):
-        # Called if "from ROOT import *" is executed in the app.
-        # Customises lookup in Python's main module to also
-        # check in C++'s global namespace
-
-        # Get caller module (jump over the facade frames)
-        num_frame = 2
-        frame = sys._getframe(num_frame).f_globals["__name__"]
-        while frame == "ROOT._facade":
-            num_frame += 1
-            frame = sys._getframe(num_frame).f_globals["__name__"]
-        caller = sys.modules[frame]
-
-        # Install the hook
-        cppyy_backend._set_cpp_lazy_lookup(caller.__dict__)
-
     def _fallback_getattr(self, name):
         # Try:
         # - in the global namespace
@@ -170,13 +154,8 @@ def _fallback_getattr(self, name):
         # The first two attempts allow to lookup
         # e.g. ROOT.ROOT.Math as ROOT.Math
 
-        if name == "__all__":
-            self._handle_import_all()
-            # Make the attributes of the facade be injected in the
-            # caller module
-            raise AttributeError()
         # Note that hasattr caches the lookup for getattr
-        elif hasattr(gbl_namespace, name):
+        if hasattr(gbl_namespace, name):
             return getattr(gbl_namespace, name)
         elif hasattr(gbl_namespace.ROOT, name):
             return getattr(gbl_namespace.ROOT, name)