docs: Document that `get_starting_timestamp` requires setting a non-null replication_key #46

	name: API Changes

	on:
	pull_request:
	paths:
	- singer_sdk/**
	- .github/workflows/api-changes.yml
	- CHANGELOG.md
	workflow_dispatch:

	concurrency:
	group: ${{ github.workflow }}-${{ github.head_ref \|\| github.run_id }}
	cancel-in-progress: true

	permissions: # added using https://github.com/step-security/secure-repo
	contents: read

	jobs:
	check-api-changes:
	name: Check API Changes
	runs-on: ubuntu-latest
	env:
	NOXSESSION: api
	steps:
	- name: Check out the repository
	uses: actions/checkout@v4
	with:
	fetch-depth: 0

	- name: Setup Python
	uses: actions/setup-python@v5
	with:
	python-version: 3.12

	- name: Install tools
	env:
	PIP_CONSTRAINT: ${{ github.workspace }}/.github/workflows/constraints.txt
	run: \|
	python -Im pip install -U pip
	pipx install griffe nox
	pipx inject nox nox-poetry
	pipx list

	- name: Set REF
	id: set-ref
	if: always() && !startsWith(github.head_ref, 'release/')
	run: \|
	echo "ref=${{ github.event.pull_request.base.sha }}" >> $GITHUB_OUTPUT

	# Check API against the latest commit on the base branch
	- name: Run Nox
	run: \|
	nox -- ${{ steps.set-ref.outputs.ref }}

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