Downgrade cachetools

Thanks to python-telegram-bot/python-telegram-bot/pull/1844 we have this hard
dependency on cachetools 4.2.2 🤦

See also
- python-telegram-bot/python-telegram-bot/pull/2757
- python-telegram-bot/python-telegram-bot/issues/2758

requirements.txt

@@ -1,6 +1,6 @@
 python-telegram-bot==13.14
 ujson==5.4.0
 pytz>=2022.4
-cachetools==5.2.0
+cachetools==4.2.2
 SQLAlchemy==1.4.41
 alembic==1.8.1

setup.py

@@ -10,7 +10,7 @@ setup(
     install_requires=[
         'python-telegram-bot>=13.0',
         'ujson>=5.2.0',
-        'cachetools>=5',
+        'cachetools>=4',
         'pytz>=2022.4',
         'SQLAlchemy>=1.4',
         'alembic>=1.8'