feat(deps): update Rspack to v1.2.6 (#4664)

Author: chenjiahan

packages/core/package.json

@@ -51,7 +51,7 @@
     "prebundle": "prebundle"
   },
   "dependencies": {
-    "@rspack/core": "1.2.5",
+    "@rspack/core": "1.2.6",
     "@rspack/lite-tapable": "~1.0.1",
     "@swc/helpers": "^0.5.15",
     "core-js": "~3.40.0",