fix: missing reference of Path

[rng70]

when pip-requirements-parser package is used to parse the requirements from the string using the RequirementsFile.from_string() method it invokes the following method

    @classmethod
    def from_string(cls, text: str) -> "RequirementsFile":
        """
        Return a new RequirementsFile from a ``text`` string.

        Since pip requirements are deeply based on files, we create a temp file
        to feed to pip even if this feels a bit hackish.
        """
        tmpdir = None
        try:
            tmpdir = Path(str(tempfile.mkdtemp()))
            req_file = tmpdir / "requirements.txt"
            with open(req_file, "w") as rf:
                rf.write(text)
            return cls.from_file(filename=str(req_file), include_nested=False)
        finally:
            if tmpdir and tmpdir.exists():
                shutil.rmtree(path=str(tmpdir), ignore_errors=True)

but the following line invokes the Path() which raises the following exception

    tmpdir = Path(str(tempfile.mkdtemp()))

exception:

Traceback (most recent call last):
  File "{directory}/site-packages/pip_requirements_parser.py", line 270, in from_string
    tmpdir = Path(str(tempfile.mkdtemp()))
             ^^^^
NameError: name 'Path' is not defined

This pr suggests that fix

[ale-rt]

This is a nice fix @pombredanne @DennisClark @tdruez