Remove unused VITEST constant import from rollup config

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jdalton

.config/rollup.base.config.mjs

@@ -36,7 +36,6 @@ const {
   NODE_MODULES,
   ROLLUP_EXTERNAL_SUFFIX,
   UTF8,
-  VITEST,
 } = constants
 
 export const EXTERNAL_PACKAGES = [