refactor(nodejs): move build cop to flakybot (#426)

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Source-Link: googleapis/synthtool@57c23fa

packages/google-cloud-bigquery-datatransfer/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-bigquery-data-transfer.git",
-        "sha": "ad02c5055d7508d206628f1676fa55012a3ea843"
+        "sha": "7671a78ad0541074364c41fb84b2ce67f7d8c674"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "363fe305e9ce34a6cd53951c6ee5f997094b54ee"
+        "sha": "57c23fa5705499a4181095ced81f0ee0933b64f6"
       }
     }
   ],