fix(sdmx_series_ecb_sup): refresh content digest after key strip

sdmx_series_ecb_sup/meta.json

@@ -57,8 +57,8 @@
   "build": {
     "built_at": "2026-06-18T22:35:32.505654Z",
     "parsimony_version": null,
-    "builder": null,
-    "content_sha256": "7dbcd38b5ab49b77eb92c3dea2e7cff52a8f9cc4169a5e3265790064f54906c4",
+    "builder": "strip-ecb-flow-prefix-keys",
+    "content_sha256": "27ada0a66de4e1f49a3970faf8f9cd45e44bd493573071d92abbb5827d6eb2bb",
     "manifest_contract_sha256": "8e9018da5cf469790bbc3b9fa0ebcd1b5c68b9ef430b201f7c7e8f2fb612e0ec"
   }
 }