Remove @netlify/plugin-lighthouse from build

Remove plugin to resolve Node.js version compatibility issue. The plugin requires Node <20 but causes conflicts with other dependencies.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: bdougie

netlify.toml

@@ -12,3 +12,14 @@
 
 [context.branch-deploy.environment]
   NODE_VERSION = "18"
+
+# Explicitly define plugins to override UI configuration
+# This prevents the @netlify/plugin-lighthouse from running
+[[plugins]]
+  package = "@netlify/plugin-nextjs"
+
+[[plugins]]
+  package = "netlify-plugin-cloudinary"
+
+[[plugins]]
+  package = "@netlify/plugin-emails"