add @swc/core to server external packages (#49721)

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Adds `@swc/core` to the default external server packages for use in
packages within node_modules. This package is useful for generating
documentation and is related to #48739. Ideally, this would be respected
by the `serverComponentsExternalPackages` options.

Co-authored-by: JJ Kasper <jj@jjsweb.site>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/next/src/lib/server-external-packages.json

@@ -2,6 +2,7 @@
   "@prisma/client",
   "@sentry/nextjs",
   "@sentry/node",
+  "@swc/core",
   "argon2",
   "autoprefixer",
   "aws-crt",