I18n: dirty workaround for PITA ghost classes remaining after unregister.

Spent again a whole day trying to understand what happens here, with no
luck. For some reasons, OperatorProperties children of unregistered
operator classes remain accessible, with their `bl_rna` member, although
that one is 100% invalid (freed memory, crashes with ASAN builds).

Funny thing is, I cannot reproduce that situation when disabling the
add-on from the py console of a Blender-with-UI.

Note: issue revealed by X3D add-on, which is still enabled in factory
settings, while not being officially supported any more, this has to be
fixed in a separate commit.

release/scripts/modules/bl_i18n_utils/bl_extract_messages.py

@@ -838,7 +838,12 @@ def dump_messages(do_messages, do_checks, settings):
     # For now, enable all official addons, before extracting msgids.
     addons = utils.enable_addons(support={"OFFICIAL"})
     # Note this is not needed if we have been started with factory settings, but just in case...
-    utils.enable_addons(support={"COMMUNITY", "TESTING"}, disable=True)
+    # XXX This is not working well, spent a whole day trying to understand *why* we still have references of
+    #     those removed calsses in things like `bpy.types.OperatorProperties.__subclasses__()`
+    #     (could not even reproduce it from regular py console in Blender with UI...).
+    #     For some reasons, cleanup does not happen properly, *and* we have no way to tell which class is valid
+    #     and which has been unregistered. So for now, just go for the dirty, easy way: do not disable add-ons. :(
+    # ~ utils.enable_addons(support={"COMMUNITY", "TESTING"}, disable=True)
 
     reports = _gen_reports(_gen_check_ctxt(settings) if do_checks else None)