chore: improve reliability of deploy integration tests (#7951)

* ci: create integration test sites in testing account

This [mechanism already
exists](https://github.com/netlify/cli/blob/b80b98f85929803fc35a08458c9327dc7ef63de0/tests/integration/utils/create-live-test-site.ts#L22-L36)
but wasn't being used here, so it was falling back to the first account the user has access to that
is returned by the accounts API.

The `netlify-integration-testing` account is properly configured to host our various integration
test sites, e.g. to avoid being rate limited.

* ci: try DEBUG_TESTS=1

* Revert "ci: try DEBUG_TESTS=1"

This reverts commit 2d186bf.

* chore: bump deploy integration test timeout and concurrency

Author: serhalp

.github/workflows/integration-tests.yml

@@ -69,6 +69,7 @@ jobs:
           # We set a flag so we can skip tests that access Netlify API
           NETLIFY_TEST_DISABLE_LIVE:
             ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork == true }}
+          NETLIFY_TEST_ACCOUNT_SLUG: 'netlify-integration-testing'
           NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}
           # NETLIFY_TEST_GITHUB_TOKEN is used to avoid reaching GitHub API limits in exec-fetcher.js
           NETLIFY_TEST_GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

tests/integration/commands/deploy/deploy.test.ts

@@ -5,7 +5,7 @@ import { fileURLToPath } from 'url'
 import { load } from 'cheerio'
 import execa from 'execa'
 import fetch from 'node-fetch'
-import { afterAll, beforeAll, describe, expect, test } from 'vitest'
+import { afterAll, beforeAll, describe, expect, test, vi } from 'vitest'
 
 import { callCli } from '../../utils/call-cli.js'
 import { createLiveTestSite, generateSiteName } from '../../utils/create-live-test-site.js'
@@ -86,7 +86,13 @@ const context: { account: unknown; siteId: string } = {
   account: undefined,
 }
 
-describe.skipIf(process.env.NETLIFY_TEST_DISABLE_LIVE === 'true').concurrent('commands/deploy', () => {
+const disableLiveTests = process.env.NETLIFY_TEST_DISABLE_LIVE === 'true'
+
+// Running multiple entire build + deploy cycles concurrently results in a lot of network requests that may
+// cause resource contention anyway, so lower the default concurrency from 5 to 3.
+vi.setConfig({ maxConcurrency: 3 })
+
+describe.skipIf(disableLiveTests).concurrent('commands/deploy', { timeout: 300_000 }, () => {
   beforeAll(async () => {
     const { account, siteId } = await createLiveTestSite(SITE_NAME)
     context.siteId = siteId