fix(deps): update dependency unique-slug to v6

Author: renovate[bot]

package.json

@@ -38,7 +38,7 @@
     "semver": "7.7.3",
     "ssri": "12.0.0",
     "tar": "7.5.2",
-    "unique-slug": "5.0.0"
+    "unique-slug": "6.0.0"
   },
   "devDependencies": {
     "@eik/eslint-config": "1.0.23",