Update astroid requirement from <2.16,>=2.4.2 to >=2.4.2,<3.1 (#17)

Updates the requirements on [astroid](https://github.com/pylint-dev/astroid) to permit the latest version.
- [Release notes](https://github.com/pylint-dev/astroid/releases)
- [Changelog](https://github.com/pylint-dev/astroid/blob/main/ChangeLog)
- [Commits](pylint-dev/astroid@astroid-2.4.2...v3.0.0)

---
updated-dependencies:
- dependency-name: astroid
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Libgenbot.egg-info/requires.txt

@@ -1,4 +1,4 @@
-astroid>=2.4.2,<2.16
+astroid>=2.4.2,<3.1
 beautifulsoup4>=4.9.1
 bibtexparser>=1.2.0
 certifi>=2020.6.20

setup.py

@@ -17,7 +17,7 @@
   download_url = 'https://github.com/suhan-paradkar/Libgenot/archive/v1.0.0-alpha.tar.gz',
   keywords = ['download-papers','google-scholar', 'libgen', 'scihub', 'scholar', 'crossref', 'papers'],
   install_requires=[
-        'astroid>=2.4.2,<2.16',
+        'astroid>=2.4.2,<3.1',
         'beautifulsoup4>=4.9.1',
         'bibtexparser>=1.2.0',
         'certifi>=2020.6.20',