Add Python 3.14 classifier to code-generated clients

[jonathan343]

Summary

This PR adds the Programming Language :: Python :: 3.14 classifier to clients generated with smithy python.

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Testing

Code Generation

Used the code generator to build a new version of the aws-sdk-bedrock-runtime client and verified the classifier is present in the generated pyproject.toml file:

classifiers = [
    "Development Status :: 2 - Pre-Alpha",
    "Intended Audience :: Developers",
    "Intended Audience :: System Administrators",
    "Natural Language :: English",
    "License :: OSI Approved :: Apache Software License",
    "Programming Language :: Python",
    "Programming Language :: Python :: 3",
    "Programming Language :: Python :: 3 :: Only",
    "Programming Language :: Python :: 3.12",
    "Programming Language :: Python :: 3.13",
    "Programming Language :: Python :: 3.14"
]

AWS SDK Bedrock Runtime

Installed aws-sdk-bedrock-runtime in a Python 3.14 virtual environment and confirmed that it successfully runs on Python 3.14. I did see a new error that will be removed with awslabs/aws-sdk-python#22

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