chore(deps): update shiki monorepo to v4

Author: renovate[bot]

package.json

@@ -63,7 +63,7 @@
     "@nuxt/module-builder": "^1.0.2",
     "@nuxt/schema": "^4.4.2",
     "@nuxt/test-utils": "^4.0.0",
-    "@shikijs/transformers": "^3.23.0",
+    "@shikijs/transformers": "^4.0.2",
     "@types/node": "^24.12.0",
     "@vue/test-utils": "^2.4.6",
     "changelogen": "^0.6.2",
@@ -74,7 +74,7 @@
     "pkg-pr-new": "0.0.66",
     "rimraf": "^6.1.3",
     "sass-embedded": "^1.98.0",
-    "shiki": "^3.23.0",
+    "shiki": "^4.0.2",
     "shiki-transformer-fold": "^0.2.0",
     "vitest": "^4.1.2"
   },