## Description
Adding the unit and integration tests from the datadog-lambda-python
repository to this repository's CI. Helps catch any changes to
dd-trace-py that would cause issues in datadog-lambda-python before
merging/release.

<!-- Provide an overview of the change and motivation for the change -->

## Testing
Gitlab. 
Verified that if trigger-serverless-lambda-tests downstream pipeline
fails, the whole ddtrace pipeline will fail and the
dd-gitlab/default-pipeline job will show as failed in the PR using [this
Gitlab
pipeline](https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-py/-/pipelines/86791461).
<!-- Describe your testing strategy or note what tests are included -->

## Risks

<!-- Note any risks associated with this change, or "None" if no risks
-->

## Additional Notes
[Related PR in
datadog-lambda-python](DataDog/datadog-lambda-python#700).
<!-- Any other information that would be helpful for reviewers -->

## Description
Adding the unit and integration tests from the datadog-lambda-python
repository to this repository's CI. Helps catch any changes to
dd-trace-py that would cause issues in datadog-lambda-python before
merging/release.

<!-- Provide an overview of the change and motivation for the change -->

## Testing
Gitlab. 
Verified that if trigger-serverless-lambda-tests downstream pipeline
fails, the whole ddtrace pipeline will fail and the
dd-gitlab/default-pipeline job will show as failed in the PR using [this
Gitlab
pipeline](https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-py/-/pipelines/86791461).
<!-- Describe your testing strategy or note what tests are included -->

## Risks

<!-- Note any risks associated with this change, or "None" if no risks
-->

## Additional Notes
[Related PR in
datadog-lambda-python](DataDog/datadog-lambda-python#700).
<!-- Any other information that would be helpful for reviewers -->