Fix sentry-native packaging workflow

[mangini]

Summary

• Pin the BCNY packaging job to Windows Server 2022, matching its Visual Studio 2022 generator.
• Pass the Windows SDK through CMAKE_SYSTEM_VERSION so synchronization APIs link correctly.
• Upgrade artifact uploads and fix the generated NuGet package glob.
• Run the workflow for stacked pull requests as well as pull requests targeting master.

Testing

• The corrected configure, build, stage, and package flow completed locally for x64 and ARM64 against sentry-native 0.16.1.
• GitHub Actions will validate the workflow independently on this PR.

Context: https://thebrowsercompany.slack.com/archives/C0BHXU3GQ4B/p1784318030072259

[mangini]

Since this is just part of the previous PR #11, I will run away with the previous review.