Update dependency @tryghost/mg-fs-utils to v0.15.6

Author: renovate[bot]

package.json

@@ -33,7 +33,7 @@
     "@tryghost/listr-smart-renderer": "0.5.15",
     "@tryghost/logging": "2.4.22",
     "@tryghost/mg-assetscraper": "0.4.16",
-    "@tryghost/mg-fs-utils": "0.15.1",
+    "@tryghost/mg-fs-utils": "0.15.6",
     "@tryghost/pretty-cli": "1.2.47",
     "@tryghost/zip": "1.1.49",
     "axios": "1.10.0",