fix: revert to netlify plugin next v4

[blushi]

Description

ref: https://regen-network.slack.com/archives/C04NR9HSNCB/p1726076912215399

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Author Checklist

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please add links to any relevant follow up issues.

I have...

• provided a link to the relevant issue or specification
• provided instructions on how to test
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

How to test

https://deploy-preview-2474--regen-website.netlify.app/

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed all author checklist items have been addressed
• reviewed code correctness and readability
• verified React components follow DRY principles
• reviewed documentation is accurate
• reviewed tests
• manually tested (if applicable)

[netlify]

✅ Deploy Preview for regen-website ready!

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🔨 Latest commit
🔍 Latest deploy log	https://app.netlify.com/sites/regen-website/deploys/66e2863ead5e5cfe2f3f3e17
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