[eng] Fake warning about changelog in nightly pipeline

[msyyc]

https://dev.azure.com/azure-sdk/public/_build/results?buildId=3922805&view=logs&j=12f1170f-54f2-53f3-20dd-22fc7dff55f9&t=e7d422da-e621-5d9c-7d76-ef2f3144435b

[tadelesh]

i think we could just remove this part:

autorest.python/eng/prepare-release-branch.js

Lines 17 to 48 in ce1f514

	const github = getOctokit(process.env.GITHUB_TOKEN ?? "");
	const prs = await github.rest.pulls.list({
	...context.repo,
	head: `${context.repo.owner}:${branchName}`,
	base: "main",
	state: "open",
	});
	console.log(
	"Found those prs",
	prs.url,
	prs.data.map((x) => x.head.ref),
	);
	const existing = prs.data[0];
	if (existing) {
	console.log("Existing, updating pr", existing.number);
	await github.rest.pulls.update({
	...context.repo,
	pull_number: existing.number,
	body: changeStatus,
	});
	} else {
	await github.rest.pulls.create({
	...context.repo,
	title: "Release changes",
	head: branchName,
	base: "main",
	body: changeStatus,
	});
	}
	} else {
	console.log("No changes to publish");
	}

. The error is from create the pr or overwrite the pr.