[Workers] Add Access changelog

[chythram05]

Summary

Adds a Workers changelog entry announcing Cloudflare Access for Workers, including account-level, Worker-level, preview deployment, and hostname-based protection options.

Screenshots (optional)

N/A

Documentation checklist

• Is there a changelog entry (guidelines)?
• The change adheres to the documentation style guide.

[cloudflare-docs-bot]

Review

✅ No issues found in commit 1307a5f.

Code Review

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_{No code review issues found.}

Conventions

Checks PR title, description, and redirect checklist.

_{No convention issues found.}

Style Guide Review

_{No style-guide issues found.}

Redirects

_{No missing redirect entries found.}

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[irvinebroque]

images from https://github.com/cloudflare/cloudflare-docs/pull/31730/changes seem helpful? or something visual?