fix(sdmx_series_ecb_dcm): refresh content digest after key strip

sdmx_series_ecb_dcm/meta.json

@@ -57,8 +57,8 @@
   "build": {
     "built_at": "2026-06-18T22:30:14.447062Z",
     "parsimony_version": null,
-    "builder": null,
-    "content_sha256": "dae925be6c33db52efd7b9ee7f28d1afc634112ed74c61bbadd40661dcb17484",
+    "builder": "strip-ecb-flow-prefix-keys",
+    "content_sha256": "2cae62b9612a2753bc250d6260b59ae01bd58aeef47043831fcaf06ed844b8d2",
     "manifest_contract_sha256": "cee5a15883b782a7053bac94e5f5b08f8f41895bddac27fec629b7fa85700b5b"
   }
 }