patch 9.1.0784: there are several problems with python 3.13

patch 9.1.0784: there are several problems with python 3.13

Problem:  there are several problems with python 3.13
Solution: fix the problems in the python3 interface (Boris Staletic)

This commit does the following things:
1) Since python 3.13.0b1, all statically defined objects are "immortal".
   Besides never getting garbage collected, this also affects reference
   counting:

   - Immportal objects have a reference count of 2^32-1.
   - Reference counting is a no-op.

   All this is considered implementation details by cpython, so
   documentation is next to non-existent.

   Relevant CPython source code:
   https://github.com/python/cpython/blob/v3.13.0/Include/object.h#L62-L107
   https://github.com/python/cpython/blob/v3.13.0/Include/object.h#L389-L391

2) Opt-out of ANSI-painted python stack traces

3) Make python error message severity more consistent

fixes: #15838
closes: #15842

Signed-off-by: Boris Staletic <boris.staletic@protonmail.com>
Signed-off-by: puremourning <puremourning@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>