feat: Add new event to upcoming events list

[jdorfman]

• Add new "AI Eng Talks ~ w/ Cloudflare, Sourcegraph & Jam.dev" event to upcoming events list
• Update events page UI with new event details

Before you merge this PR, please review the following:

Blog post

• [ ] Checked title case (This is correct. This Is Not Correct)
• [ ] Updated publishDate
• [ ] Updated authors
• [ ] Updated and checked slug
• [ ] Proofread for spelling and grammar errors
• [ ] Checked for consistent tone and voice throughout via Grammarly
• [ ] Ensured all links are working correctly
• [ ] Added relevant tags and categories
• [ ] Optimized meta description
• [ ] Included a new hero and social/OG image
• [ ] Uploaded images to Google Storage
• [ ] Formatted text for readability (headings, bullet points, etc.)
• [ ] Added image alt text
• [ ] Ran Markdown linter

Other

• [x] This is not a blog post

[netlify[bot]]

✅ Deploy Preview for sourcegraph ready!

Name	Link
🔨 Latest commit	e218b49ef16cd47fb697ff29cea79faa574acc40
🔍 Latest deploy log	https://app.netlify.com/sites/sourcegraph/deploys/6712d7f6c7794d000841a240
😎 Deploy Preview	https://deploy-preview-7321--sourcegraph.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.