Limit the number of threads for external memory. #5171

	name: XGBoost-Python-Wheels

	on: [push, pull_request]

	permissions:
	contents: read # to fetch code (actions/checkout)

	jobs:
	python-wheels:
	name: Build wheel for ${{ matrix.platform_id }}
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	include:
	- os: macos-latest
	platform_id: macosx_x86_64
	- os: macos-latest
	platform_id: macosx_arm64
	steps:
	- uses: actions/checkout@e2f20e631ae6d7dd3b768f56a5d2af784dd54791 # v2.5.0
	with:
	submodules: 'true'
	- name: Setup Python
	uses: actions/setup-python@7f80679172b057fc5e90d70d197929d454754a5a # v4.3.0
	with:
	python-version: "3.8"
	- name: Build wheels
	run: bash tests/ci_build/build_python_wheels.sh ${{ matrix.platform_id }} ${{ github.sha }}
	- name: Extract branch name
	shell: bash
	run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
	id: extract_branch
	if: github.ref == 'refs/heads/master' \|\| contains(github.ref, 'refs/heads/release_')
	- name: Upload Python wheel
	if: github.ref == 'refs/heads/master' \|\| contains(github.ref, 'refs/heads/release_')
	run: \|
	python -m pip install awscli
	python -m awscli s3 cp wheelhouse/*.whl s3://xgboost-nightly-builds/${{ steps.extract_branch.outputs.branch }}/ --acl public-read
	env:
	AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID_IAM_S3_UPLOADER }}
	AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY_IAM_S3_UPLOADER }}

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