As per https://peps.python.org/pep-0394/, the python binary can be one
of the following options:
- Python 2
- Python 3
- Not exist
All of the scripts in libxml2 use 'python', which may not exist.
As Python 2 reached EOL on the 1st January 2020, it's safe to move the
scripts to use python3 explicitly.
* Makefile.am configure.in xmldwalk.c xmlreader.c
include/libxml/Makefile.am include/libxml/xmldwalk.h
include/libxml/xmlversion.h.in: removing xmldwalk module
since it got merged with the xmlreader.
* parser.c: cleanup
* win32/libxml2.def.src python/libxml2class.txt doc/libxml2-api.xml:
rebuilt the API
* python/tests/Makefile.am python/tests/reader7.py
python/tests/walker.py: adding regression testing for the
new xmlreader APIs, new APIs for reader creation, including
makeing reader "walker" operating on preparsed document trees.
Daniel