Hopefully fix:
The lambda layer can be published as follows for dev work:
    aws lambda --output json publish-layer-version --layer-name 'runner-dev-elastic-apm-python' --description 'runner dev Elastic APM Python agent lambda layer' --zip-file 'fileb://build/dist/elastic-apm-python-lambda-layer.zip'
Run actions/upload-artifact@v4
  with:
    name: build-distribution
    path: ./build/
    if-no-files-found: error
    compression-level: 6
    overwrite: false
  env:
    ...
With the provided path, there will be 636 files uploaded
Artifact name is valid!
Root directory input is valid!
Error: Failed to CreateArtifact: Received non-retryable error: Failed request: (409) Conflict: an artifact with this name already exists on the workflow run