Add compatibility with pip 24

[dpvDuncan]

Currently, when using Pur directly from Python as per the documentation:
>>> from pur import update_requirements
>>> print([x[0]['message'] for x in update_requirements(input_file='requirements.txt').values()])

there is an error with pip version 24, and maybe 23 too:

Traceback (most recent call last):
File "C:\Users\me\requirements_update.py", line 73, in
for x in update_requirements(
^^^^^^^^^^^^^^^^^^^^
File "C:\Users\me\AppData\Local\Programs\Python\Python312\Lib\site-packages\pur_init_.py", line 201, in update_requirements
update_requirements(
File "C:\Users\me\AppData\Local\Programs\Python\Python312\Lib\site-packages\pur_init.py", line 267, in update_requirements
for line, req, spec_ver, latest_ver in requirements:
File "C:\Users\me\AppData\Local\Programs\Python\Python312\Lib\site-packages\pur_init.py", line 387, in get_requirements_and_latest
for parsed_req, orig_line in requirements:
File "C:\Users\me\AppData\Local\Programs\Python\Python312\Lib\site-packages\pur_init.py", line 434, in _parse_requirements
for parsed_line, orig_line in parser.parse(filename, constraint):
File "C:\Users\me\AppData\Local\Programs\Python\Python312\Lib\site-packages\pip_internal\req\req_file.py", line 332, in parse
yield from self._parse_and_recurse(
^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: PatchedRequirementsFileParser._parse_and_recurse() takes 3 positional arguments but 4 were given

It seems that pip._internal.req.req_file._parse_and_recurse, which is overridden in pur (in class PatchedRequirementsFileParser) evolved, and it no requires 4 inputs instead of 3 (parsed_files_stack seems to have been added)

This PR aims to quickly make the overriding method compatible with Pip, no matter the version.

[alanhamlett]

Thanks!