ci: run preview deploys concurrently

[zeke]

This PR makes the two wrangler deploy calls in the Deploy Preview job's "Deploy to Cloudflare Workers" step run concurrently instead of sequentially.

Each PR preview is deployed twice, once under the short commit SHA and once under the branch-slug name, to the same dispatch namespace. These deploys are independent of each other, but currently run back-to-back in a single shell step, roughly doubling the time of that step (observed ~5m18s across two deploys on a recent run).

This backgrounds both wrangler deploy invocations and waits on each, so the step fails the same way as before if either deploy fails, but the wall-clock time should be close to that of a single deploy.

[cloudflare-docs-bot]

Review

⚠️ 1 warning found in commit 8a99842.

👉 Fix in your agent 👈

Fix the following review findings in PR #33386 (https://github.com/cloudflare/cloudflare-docs/pull/33386).

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After triaging, follow this order:
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---

## Code Review

### Warnings (1)

#### CR-d92421014d76 · Background job status lost on first failure
- **File:** `.github/workflows/ci.yml` line 296
- **Issue:** The step runs under GitHub Actions' default shell (`bash -e -o pipefail`). If the short-SHA deploy fails, `wait "$short_sha_pid"` returns non-zero and `set -e` terminates the script immediately, so `wait "$branch_slug_pid"` (line 297) never executes. The branch-slug deploy is left running as an orphaned background process and its exit status is never collected, so a failure of that deploy goes unreported and the process may outlive the step.
- **Fix:** Capture both exit statuses before letting the script exit, e.g. `set +e; wait "$short_sha_pid"; s1=$?; wait "$branch_slug_pid"; s2=$?; set -e; exit $((s1 || s2))`, so both deploys are always awaited and either failure fails the step.

Code Review

This code review is in beta and may not always be helpful — use your judgment.

Warnings (1)

File

Issue

.github/workflows/ci.yml line 296

Background job status lost on first failure — The step runs under GitHub Actions' default shell (bash -e -o pipefail). If the short-SHA deploy fails, wait "$short_sha_pid" returns non-zero and set -e terminates the script immediately, so wait "$branch_slug_pid" (line 297) never executes. The branch-slug deploy is left running as an orphaned background process and its exit status is never collected, so a failure of that deploy goes unreported and the process may outlive the step. Fix: Capture both exit statuses before letting the script exit, e.g. set +e; wait "$short_sha_pid"; s1=$?; wait "$branch_slug_pid"; s2=$?; set -e; exit $((s1 || s2)), so both deploys are always awaited and either failure fails the step.

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[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/.github/	@ahaywood, @colbywhite, @MohamedH1998, @mvvmm, @cloudflare/content-engineering

[github-actions]

Preview URL: https://8a998426.preview.developers.cloudflare.com
Preview Branch URL: https://ci-parallel-preview-deploys.preview.developers.cloudflare.com

[cloudflare-workers-and-pages]

🚀 Deploying Preview to Cloudflare 🚀

Preview URL: https://ci-parallel-preview-deploys.previews.developers.cloudflare.com (commit 8a99842)

This URL reflects your latest Preview deployment

Preview Deployments by commit

Status	Deployment URL	Commit	Updated (UTC)	See this deployment's details
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://27a53e22.previews.developers.cloudflare.com	8a99842	2026-09-10T22:20:24.522Z	Visit the dashboard ↗

[mvvmm]

I'm fine w the review finding.