Dart

Remove generated `StatusCode` (#703) #751

Job	Run time
analyze (3.2.0)	29s
analyze (dev)	58s
test (ubuntu-latest, 3.2.0, vm)	31s
test (ubuntu-latest, 3.2.0, chrome)	1m 54s
test (ubuntu-latest, dev, vm)	28s
test (ubuntu-latest, dev, chrome)	1m 47s
test (macos-latest, 3.2.0, vm)	29s
test (macos-latest, dev, vm)	35s
test (windows-latest, 3.2.0, vm)	54s
test (windows-latest, dev, vm)	51s
	8m 56s

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