See
[botocore](https://github.com/boto/botocore/blob/0b28c3155f160a68fd901c9eb80a7a6a45a16216/setup.cfg#L8)

Sometimes after switching branches, `importlib.metadata("sentry-sdk")`
would point to the wrong metadata (SDK 2.x instead of 3.x), which in
turn meant toxgen would think the SDK supports different Python versions
than it should.

Closes #4556

Use regex to check line number instead of hard coding it

Fixes GH-4454
#4454
<!-- Describe your PR here -->

Changed the loguru test_just_log test to use a regex for the log format instead of a hard-coded line number.

Currently this thread will wait for `sleep(self.flush_interval)` to end
before
checking `self._running`. We can do better by using an Event.

Now it will wait for `self.flush_interval` or until
`self.__shutdown_requested`
is set, whichever is shorter.

The `model` parameter can be a string or an object of the model itself.
If it is a model, get the models name from the `.model` attribute.

Store AI token usage in `span.data` instead of deprecated
`measurements`.

In `relay` there is already code in place that copies the data from the
deprecated `span.measurements` to `span.data` and uses `span.data` for
calculating the cost of token usage. So this PR can be deployed in a
minor without risk.

See also `relay` PR: getsentry/relay#4768

fixes 

```
PytestCollectionWarning: cannot collect test class 'TestSpanClientReports' because it has a __init__ constructor (from: tests/test_client.py)
    class TestSpanClientReports:
```

don't think this one is needed at all

part of #4538

again see no reason why we need these

part of #4538

While implementing #4479, I noticed that our Langchain integration lacks
support for the `local_callbacks` having type `BaseCallbackManager`,
which according to the type hint is possible.

This change adds support for this case.

Fixes #4537

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Remove non-user-facing changes