fix(css): ensure order of extracted CSS

Without this the order of the extracted CSS rules is defined by the order `renderChunk` of the css plugin is called.
So with this the order of CSS rules is always in order of the output chunks of the bundle.

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

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

@@ -7,6 +7,7 @@ import postcssrc from 'postcss-load-config'
 import type {
   ExistingRawSourceMap,
   ModuleFormat,
+  OutputAsset,
   OutputChunk,
   RenderedChunk,
   RollupError,
@@ -903,17 +904,19 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
             .map((chunk) => [chunk.preliminaryFileName, chunk]),
         )
 
-        function collect(fileName: string) {
-          const chunk = bundle[fileName]
+        function collect(chunk: OutputChunk | OutputAsset) {
           if (!chunk || chunk.type !== 'chunk' || collected.has(chunk)) return
           collected.add(chunk)
 
-          chunk.imports.forEach(collect)
+          chunk.imports.forEach((importName) => collect(bundle[importName]))
           css += chunkCSSMap.get(chunk.preliminaryFileName) ?? ''
         }
 
-        for (const chunkName of chunkCSSMap.keys())
-          collect(prelimaryNameToChunkMap.get(chunkName)?.fileName ?? '')
+        for (const chunk of Object.values(bundle)) {
+          if (chunk.type === 'chunk' && (chunk as OutputChunk).isEntry) {
+            collect(chunk)
+          }
+        }
 
         return css
       }