fix(sdmx_series_ecb_est): refresh content digest after key strip

sdmx_series_ecb_est/meta.json

@@ -30,8 +30,8 @@
   "build": {
     "built_at": "2026-06-18T22:30:34.030936Z",
     "parsimony_version": null,
-    "builder": null,
-    "content_sha256": "a6ab786e2895502f44692eb9fd326c2b1d773a1ab8597961b5ecb81075632a3e",
+    "builder": "strip-ecb-flow-prefix-keys",
+    "content_sha256": "47c07c731c29b2e7facf517e61ef480baf8e7d00b6c4b5a38260d01260340392",
     "manifest_contract_sha256": "a7c927b7a9ab7bd85acd155846f44b1efd17738dcf4aee2096a762c3883c4e16"
   }
 }