refactor(nodejs): move build cop to flakybot (#838)

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Source-Link: googleapis/synthtool@57c23fa

Author: yoshi-automation

handwritten/bigtable/.kokoro/samples-test.sh

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-bigtable.git",
-        "sha": "99b7617e215126fc36ef3c3ebefb244e0d8d2242"
+        "sha": "73aa7345f935645063c1123a681a529d66f93bd7"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "363fe305e9ce34a6cd53951c6ee5f997094b54ee"
+        "sha": "57c23fa5705499a4181095ced81f0ee0933b64f6"
       }
     }
   ],