fix(aws): Inject scopes in TimeoutThread exception with AWS lambda

[alexander-alderman-webb]

Description

Missing tags and breadcrumbs on sentry_sdk>=2.26.1 when lambda functions time out are an unintended consequences of 2d392af

You can verify the change with the new unit test.

To test manually:

1. Clone this repo: https://github.com/getsentry/python-lambda-timeout-repro/tree/main.
2. If you do not already have the sam cli installed, follow the instructions to install the cli: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/install-sam-cli.html
3. Stick a DSN in sam-app/hello_world/app.py.
4. Use your local clone of the SDK in the lambda. In my case, I updated sam-app/hello_world/requirements.txt with

- sentry_sdk==2.26.1
+ /Users/alex/code/sentry-repos/sentry-python

Follow the commands to run the lambda in the README.md of the project. That is, in separate terminals run

sam local start-lambda --debug --template .aws-sam/build/template.yaml
sam local invoke HelloWorldFunction

Issues

More information about how I found the bug are described in #4912.

Closes #4894

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community

[alexander-alderman-webb]

Can the mechanism be changed?

Keeping type=threading would keep it consistent with previous behaviour.

Changing this could help us distinguish AWS lambda timeout exceptions with exceptions caught by the threading integration that are unrelated to AWS lambda timeouts.