chore(alert banner): Update for HD23 in-person tickets being sold out

[EnMod]

What

This PR updates the terraform.io alert banner to showcase the selling out of all HashiDays in-person tickets.

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Merge Checklist

If items do not apply to your changes, add (N/A) and mark them as complete.

Pull Request

• One or more labels describe the type of change (e.g. clarification) and associated product (e.g. tfc).
• Description links to related pull requests or issues, if any. (N/A)

Content

• Redirects have been added for moved, renamed, or deleted pages. (N/A)
• Sidebar navigation files have been updated for added, deleted, reordered, or renamed pages. (N/A)
• Links to related content where appropriate (e.g., API endpoints, permissions, etc.). (N/A)
• Pages with related content are updated and link to this content when appropriate. (N/A)
• New pages have metadata (page name and description) at the top. (N/A)
• New images are 2048 px wide. They have HashiCorp standard annotation color (#F92672) and format (rectangle with rounded corners), blurred sensitive details (e.g. credentials, usernames, user icons), and descriptive alt text in the markdown for accessibility. (N/A)
• New code blocks have the correct syntax and line breaks to eliminate horizontal scroll bars. (N/A)
• UI elements (button names, page names, etc.) are bolded. (N/A)
• The Vercel website preview successfully deployed. (N/A)

Reviews

• I or someone else reviewed the content for technical accuracy.
• I or someone else reviewed the content for typos, punctuation, spelling, and grammar.

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Name	Status	Preview	Updated (UTC)
terraform-website	✅ Ready (Inspect)	Visit Preview	May 16, 2023 4:44pm