perf: define viteMetadata instead of assign (#106)

Author: sapphi-red

packages/vite/src/node/build.ts

@@ -1359,7 +1359,11 @@ function injectChunkMetadata(
       __modules: chunk.modules,
     })
   }
-  chunk.viteMetadata = chunkMetadataMap.get(key)
+  // define instead of assign to avoid detected as a change
+  // https://github.com/rolldown/rolldown/blob/f4c5ff27799f2b0152c689c398e61bc7d30429ff/packages/rolldown/src/utils/transform-to-rollup-output.ts#L87
+  Object.defineProperty(chunk, 'viteMetadata', {
+    value: chunkMetadataMap.get(key),
+  })
   Object.defineProperty(chunk, 'modules', {
     get() {
       return chunk.viteMetadata!.__modules