Close survey on futures codelab (#1944)

Author: legalcodes

src/codelabs/async-await/index.md

@@ -507,5 +507,3 @@ are some suggestions for where to go next:
 [documentation guide]: /guides/language/effective-dart/documentation
 [usage guide]: /guides/language/effective-dart/usage
 [design guide]: /guides/language/effective-dart/design
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-<iframe src="https://google.qualtrics.com/jfe/form/SV_5z1y0FziMqwMBZX" height="1025px" width="100%" style="margin-top: 10px;border: 0px;"></iframe>