大事なことを書き忘れておりました！
こちらのケーキ、今週末の日曜日まではGST込みで$8.80とさせていただきます🙇‍♀️（8月9日以降は+GST）
Grand Jeté
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BOULEVARD
gst 8 80 8 9 gst
  [
    {"relatedness": False, "type": "none", "explanation": "This post does not relate to a maintenance report feedback for a public flat house."},
    ]

It seems that the post "gst 8 80 8 9 gst" does not contain any information related to a maintenance report feedback for a public flat house. The post consists of a series of numbers and letters, which do not form a coherent message or request. Therefore, the answer is that the post does not relate to a maintenance report feedback for a public flat house.