Add ; x-http2-push-only to the CSS-Font-Link header

[trieloff]

To fix the lighthouse warnings see https://docs.fastly.com/en/guides/http2-server-push

[adobe-bot]

🎉 This issue has been resolved in version 1.9.5 🎉

The release is available on:

• v1.9.5
• GitHub release

Your semantic-release bot 📦🚀

[trieloff]

@rofe we may need to roll this change back, as the real underlying issue is that our font kit in theblog contained too many unused fonts.