[CP] Fix Windows powershell script not being able to update Dart SDK #132718
Description
Issue Link
Commit Hash
Target
beta (3.14)
PR Link
Changelog Description
Ensure the existing //flutter/bin/cache/LICENSE.dart_sdk_archive.md is moved before unzipping a new Dart SDK, preventing the powershell script from hanging.
Impacted Users
Windows developers
Impact Description
Once users get on an affected version, their NEXT flutter upgrade will leave them in a bad state where they can't extract the new Dart SDK. Re-running the tool will not help, as the batch entrypoint will still detect the Dart SDK is not present, and then run the powershell script to download and unzip the Dart SDK.
Workaround
The workaround would be to run flutter upgrade until it hangs, kill the process, delete //flutter/bin/cache/LICENSE.dart_sdk_archive.md, and then re-run to complete extracting the zip and building the tool.
Risk
medium
Test Coverage
yes
Validation Steps
No response