Use weakref in dedupe where possible

[sl0thentr0py]

We cannot use weakref always since built-in exception types like ZeroDivisionError raise a TypeError.
This makes the memory usage at least a little better for custom exception types.

Issues

• resolves: Memory leak during exception logging #3165
• resolves: PY-17

[linear]

PY-17 Memory leak during exception logging

[codecov]

✅ All tests passed in 2585.21s

[sl0thentr0py]

with the fix in this PR, the code from #3165 (comment)

gives

before

(.venv) [neel@vheissu vanilla]$ python app.py 
ERROR:root:Exception logging
Traceback (most recent call last):
  File "/run/media/neel/m2/sentry/sentry_sample_apps/python/vanilla/app.py", line 16, in <module>
    raise CustomException('Custom Exception')
CustomException: Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
Custom Exception
^CException was garbage collected!

after

(.venv) [neel@vheissu vanilla]$ python app.py 
ERROR:root:Exception logging
Traceback (most recent call last):
  File "/run/media/neel/m2/sentry/sentry_sample_apps/python/vanilla/app.py", line 16, in <module>
    raise CustomException('Custom Exception')
CustomException: Custom Exception
Exception was garbage collected!
None
None
None
None

[antonpirker]

Nice!