fix(sdmx_series_ecb_icb): refresh content digest after key strip

sdmx_series_ecb_icb/meta.json

@@ -54,8 +54,8 @@
   "build": {
     "built_at": "2026-06-18T22:31:23.591288Z",
     "parsimony_version": null,
-    "builder": null,
-    "content_sha256": "45a08ebbc4a0965cbe430904924be2bbdffbbcf1e9b7cacc8907d37b0de161f3",
+    "builder": "strip-ecb-flow-prefix-keys",
+    "content_sha256": "ef94b79dde363c72a91a7d8a449d184810226b8eea377028cdfa062a239452d1",
     "manifest_contract_sha256": "abbcfc3c77c822472b0205c33f208f50023c3401d736f8f19ac3430d2f4f6abb"
   }
 }