fix(vite-plugin): Fix HMR in Windows (#1093)

* fix(vite-plugin): fix HMR in Windows

* chore: add changeset

Author: kasmacioma

.changeset/pink-students-grab.md

@@ -0,0 +1,5 @@
+---
+'@vanilla-extract/vite-plugin': patch
+---
+
+Fix HMR in Windows by normalizing paths from `watchFiles`

packages/vite-plugin/src/index.ts

@@ -179,7 +179,7 @@ export function vanillaExtractPlugin({
       for (const file of watchFiles) {
         // In start mode, we need to prevent the file from rewatching itself.
         // If it's a `build --watch`, it needs to watch everything.
-        if (config.command === 'build' || file !== validId) {
+        if (config.command === 'build' || normalizePath(file) !== validId) {
           this.addWatchFile(file);
         }
       }