You just asked your question 13 years and 4 months too early! This feature is now available in preview, described here:
https://github.com/dotnet/sdk/blob/main/documentation/general/dotnet-run-file.md
MS Build 2025 video on this feature: https://youtu.be/98MizuB7i-w?si=FIsCbsoYrPGyiUdb