Provide support for Python 3.12

[asmith-elastic]

Describe the enhancement:

As AWS Lambda has added support for Python 3.12, it would be beneficial for the Elasticsearch Serverless Forwarder (ESF) to also support this version. Updating to Python 3.12 would also provide a longer window of support, as older Python versions progress to end-of-life status.

I also wanted to address the current import error one will encounter when attempting to use Python 3.12 with ESF:

[ERROR] Runtime.ImportModuleError: Unable to import module 'main_aws': No module named 'orjson.orjson'

This error points to a compatibility issue with dependencies, which further reinforces the need for official support and testing of the new runtime version.