ctypes: Remove misleading comment about tuple support in _as_parameter_ and add regression test

[CodeMaverick-143]

Bug report

Bug description:

Modules/_ctypes/callproc.c contained a comment (marked XXX) stating that as_parameter
allows constructing arbitrary tuples and passing them, describing this convention as "dangerous".
Analysis confirms that
ctypes
does not support returning tuples from as_parameter for default conversions. Attempting to do so raises a "TypeError" (wrapped in an ArgumentError), meaning the described security risk does not exist in the current codebase.

CPython versions tested on:

3.13

Operating systems tested on:

macOS

Linked PRs

• Gh-142174: Explicitly disallow _as_parameter_ returning tuples #142175