devicehost: stop re-signing and rely on MSIRMSHUTDOWN for file-in-use handling

[benhillis]

Cherry-pick of #40075 onto feature/wsl-for-apps.

This change:

• Sources wsldevicehost.dll directly from the DeviceHost package output (already signed), removing redundant re-signing
• Removes wsldevicehost.dll from the build-stage publish pattern
• Removes the CMake staging link for wsldevicehost.dll
• Bumps Microsoft.WSL.DeviceHost to 1.2.10-0
• Relies on the existing MSIRMSHUTDOWN=1 MSI property to handle file-in-use scenarios during install, instead of a custom action

[Copilot]

Pull request overview

This PR updates the WSL MSI packaging/staging flow to stop re-signing wsldevicehost.dll and instead consume the already-signed binary directly from the Microsoft.WSL.DeviceHost NuGet package, while relying on Windows Installer’s Restart Manager behavior for in-use file replacement.

Changes:

• Bump Microsoft.WSL.DeviceHost NuGet dependency to 1.2.10-0.
• Source wsldevicehost.dll directly from the DeviceHost package output and remove the local CMake staging link + build-stage publish pattern entry.
• Enable MSIRMSHUTDOWN=1 in the MSI to improve handling of file-in-use scenarios.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
packages.config	Updates DeviceHost package version used by the build.
msipackage/package.wix.in	Switches the wsldevicehost.dll source path to the NuGet package output and enables MSIRMSHUTDOWN=1.
CMakeLists.txt	Removes the staging symlink creation for wsldevicehost.dll in the build output.
.pipelines/build-stage.yml	Stops publishing wsldevicehost.dll from the build-stage artifacts.

[Copilot]

MSIRMSHUTDOWN is now hard-coded to 1, but the preceding comment says this is only “during upgrade”. With the property set unconditionally at the package level it can also affect first-time installs/repairs. Either update the comment to match the new behavior, or conditionally set MSIRMSHUTDOWN=1 only for upgrade scenarios (e.g., when WIX_UPGRADE_DETECTED/UPGRADINGPRODUCTCODE indicates an upgrade).

[OneBlue]

Overriding to get a release build sooner. The wslc test passed a full testpass was done on master