Add workflow to welcome first-time contributors #17387

Job	Run time
Packaging test	1s
Doc test	1s
Format check	1s
Lint check	1s
Changed files test	1s
Type check	1s
Notebook formatting	1s
Build protos	1s
Misc check	1s
Coverage check	1s
Isolated pytest Ubuntu	1s
Pytest MacOS (3.10)	1s
Pytest MacOS (3.11)	1s
Changed Notebooks Isolated Test against Cirq stable (partition-0)	1s
Pytest MacOS (3.12)	1s
Changed Notebooks Isolated Test against Cirq stable (partition-1)	1s
Pytest Ubuntu (3.10)	1s
Changed Notebooks Isolated Test against Cirq stable (partition-2)	1s
Check consistency of requirements	1s
Pytest Ubuntu (3.11)	1s
Changed Notebooks Isolated Test against Cirq stable (partition-3)	1s
Pytest Ubuntu (3.12)	1s
Pytest Ubuntu with NumPy-2 (3.10)	1s
Pytest Ubuntu with NumPy-2 (3.11)	1s
Pytest Ubuntu with NumPy-2 (3.12)	1s
Shell check	1s
Pytest Ubuntu with NumPy-2 (3.13)	1s
Pytest Windows (3.10)	3s
Pytest Windows (3.11)	1s
Pytest Windows (3.12)	1s
Notebook Tests against PR	1s
Bundle file consistency	1s
Typescript tests coverage	1s
Typescript lint check	1s
Typescript tests	1s
	37s

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