fix: don't append /@fs/ for bare imports (#14995)

Author: sapphi-red

packages/vite/src/node/plugins/importAnalysis.ts

@@ -335,7 +335,8 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
           url = resolved.id.slice(root.length)
         } else if (
           depsOptimizer?.isOptimizedDepFile(resolved.id) ||
-          fs.existsSync(cleanUrl(resolved.id))
+          (path.isAbsolute(cleanUrl(resolved.id)) &&
+            fs.existsSync(cleanUrl(resolved.id)))
         ) {
           // an optimized deps may not yet exists in the filesystem, or
           // a regular file exists but is out of root: rewrite to absolute /@fs/ paths