SAM build fails due to unsupported runtime versions in the template

The runtime versions specified in the [SAM template](https://github.com/aws-samples/amazon-personalize-samples/blob/master/next_steps/operations/streaming_events/template.yaml#L96-L109) are no longer supported. Specifically:

* [python3.7](https://github.com/aws-samples/amazon-personalize-samples/blob/master/next_steps/operations/streaming_events/template.yaml#L96)
* [nodejs12.x](https://github.com/aws-samples/amazon-personalize-samples/blob/master/next_steps/operations/streaming_events/template.yaml#L109)

**Error Message:**

```python
Build Failed

Error: Building functions with python3.7 is no longer supported
Error: Error: Building functions with nodejs12.x is no longer supported
```

**Suggested fix**: update the runtimes to any of the supported versions:
* python3.8, python3.9, python3.10, python3.11, python3.12 or python3.13
* nodejs18.x, nodejs20.x, or nodejs22.x

Open next_steps/operations/streaming_events/template.yaml at lines 96-109 and review the Python and Node.js runtime entries. Run the SAM build to reproduce the failure, update both entries to supported runtime versions, and run the build again to confirm it succeeds without unsupported-runtime errors.

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