Prioritize PR checks that don't require REST API calls first

[charlietsai]

Similar to #305, I'm looking into ways to reduce API calls made.

I can see here in prNeedsUpdate:

autoupdate/src/autoupdater.ts

Line 245 in 01c66da

async prNeedsUpdate(pull: PullRequest): Promise<boolean> {

that we have this API call this.octokit.rest.repos.compareCommitsWithBasehead relatively early on:

autoupdate/src/autoupdater.ts

Lines 263 to 272 in 01c66da

	try {
	const { data: comparison } =
	await this.octokit.rest.repos.compareCommitsWithBasehead({
	owner: pull.head.repo.owner.login,
	repo: pull.head.repo.name,
	// This base->head, head->base logic is intentional, we want
	// to see what would happen if we merged the base into head not
	// vice-versa. This parameter expects the format {base}...{head}.
	basehead: `${pull.head.label}...${pull.base.label}`,
	});

We don't check for PR_READY_STATE and PR_FILTER until further down, so this API call is made for all PRs that are still open. However, many of these checks would have returned false early on if they were checked first.

I don't think compareCommitsWithBasehead needs to run unless all the conditions pass? Could we change it so that it doesn't run until the end?