fix(build): apply resolve.external/noExternal to server environments

[bluwy]

Description

Apply resolve.external/noExternal to server environments during build. Previously it only applied if config.build.ssr is set, and I'm not sure if that's intentional. Perhaps it's related to this:

vite/playground/environment-react-ssr/vite.config.ts

Lines 41 to 45 in dee60ba

	// [feedback]
	// is this still meant to be used?
	// for example, `ssr: true` seems to make `minify: false` automatically
	// and also externalization.
	ssr: true,