chore(deps): update dependency chai to v6

Author: renovate[bot]

package.json

@@ -29,7 +29,7 @@
     "@types/prettier": "^3.0.0",
     "@typescript-eslint/parser": "^8.19.0",
     "astro": "^5.1.2",
-    "chai": "^5.1.2",
+    "chai": "^6.0.0",
     "eslint": "^9.17.0",
     "eslint-plugin-astro": "^1.3.1",
     "mocha": "^11.0.1",