feat(flutter): update profiling docs (#14628)

Make the wording a bit clearer

Author: buenaflor

docs/platforms/dart/guides/flutter/profiling/index.mdx

@@ -12,7 +12,7 @@ The profiling feature captures profiles across multiple language layers, includi
 
 <Alert>
 
-Flutter Profiling alpha is available for **iOS** and **macOS** since SDK version `7.12.0`.
+Flutter Profiling is currently in Alpha and available only for **iOS** and **macOS**, requiring SDK version 7.12.0 or later.
 
 </Alert>