ci: add workflow for lambda layer publish

[dbschmigelski]

Description

This pull request introduces new automated workflows for publishing and managing Strands Agents Lambda layers across AWS regions, Python versions, and architectures.

The publishing workflow, defined in publish-lambda-layer.yml, automates layer creation across 136 distinct variants, encompassing 17 regions, 2 architectures, and 4 Python versions. To prevent accidental deployments, the workflow requires explicit version confirmation through the phrase "Create Lambda Layer {version}".

For cases where layer access needs to be restricted, we've implemented a yanking workflow in yank-lambda-layer.yml.

The implementation supports 136 Lambda layers, covering combinations of Python versions (3.10, 3.11, 3.12, 3.13), architectures (x86_64, aarch64), and all 17 non opt-in AWS regions. Each layer follows the naming convention "strands-agents-py{VERSION}-{ARCH}-all" and maintains version synchronization across all variants.

This PR uses the same strategy used in https://docs.aws.amazon.com/powertools/python/latest/getting-started/install/#lambda-layer where layers are synced to version 27, currently, across all variants.

Note: The review and configuration of the IAM role will be conducted outside of the GitHub workflow system to ensure proper security controls and compliance with organizational policies.

Related Issues

#636

Documentation PR

strands-agents/docs#255

Type of Change

New feature

Testing

How have you tested the change? Verify that the changes do not break functionality or introduce warnings in consuming repositories: agents-docs, agents-tools, agents-cli

Tested in dbschmigelski/sdk-python running both publishing and yanking with various configurations.

https://github.com/dbschmigelski/sdk-python/actions/runs/17740370035
https://github.com/dbschmigelski/sdk-python/actions/runs/17740080550

• I ran hatch run prepare

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published

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[Unshure]

Looked into some limitations around lambda layers, and it looks like there is a default limit of 75GB for code storage across lambda layers and lambda code. If we are bundling 8 versions of the layer per region, do we know when we are at risk of hitting this limit?

Also, can we create an issue to track adding an integ test for the deployed lambda layer?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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2 approvers, stale review