chore(deps): update dependency @rslib/core to ^0.21.0 (#38)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -42,7 +42,7 @@
     "@biomejs/biome": "^1.9.4",
     "@playwright/test": "^1.59.1",
     "@rsbuild/core": "1.7.5",
-    "@rslib/core": "^0.20.3",
+    "@rslib/core": "^0.21.0",
     "@types/node": "^24.12.2",
     "nano-staged": "^0.9.0",
     "playwright": "^1.59.1",