Steps to reproduce

1. Install mypy
2. Write import telegram.ext and var = telegram.ext.CallbackContext()
3. Run mypy

Expected behaviour

Only the error

Too few arguments for "CallbackContext"  [call-arg] (3:7)

should be thrown.

I'm pretty sure this used to be ok in a previous version.

Actual behaviour

The errors

Too few arguments for "CallbackContext"  [call-arg] (3:7)
Need type annotation for 'var'  [var-annotated] (3:7)

are thrown.

Configuration

Operating System:

macOS 11.4 (20F71)

Version of Python, python-telegram-bot & dependencies:

python-telegram-bot 13.7
Bot API 5.3
certifi 2020.12.05
Python 3.9.5 (default, May  4 2021, 03:36:27)  [Clang 12.0.0 (clang-1200.0.32.29)]

Logs

Insert logs here (if necessary)