feat(installer): disable restart manager in Agent MSI

[thenextman]

This PR disables the Windows Restart Manager for the Agent MSI.

The restart manager is intended to reduce reboots due to locked files; and will attempt to shutdown and relaunch executables that are using files the installer will delete and recreate. It prompts the user interactively in this case and offers them the choice to attempt a shutdown/restart of the relevant applications (requires that the applications integrate with the restart manager) or to allow a reboot.

Both the Agent tray application and the session executable trigger the restart manager, but in both cases we will manage things ourselves here. We don't want to prompt the user.

• Disable the restart manager. This makes Windows Installer fall back to the old-style "files in use" dialog, which, importantly, won't trigger for these executables - because they don't have a main window
• Do nothing for DevolutionsSession.exe; it will be terminated when the DevolutionsAgent.exe service is shutdown by the installer
• Manually terminate the DevolutionsDesktopAgent.exe. Since this executable doesn't respond to WM_CLOSE, this will always end up being a process Kill, but that doesn't really matter for now

[github-actions]

Let maintainers know that an action is required on their side

• Add the label release-required Please cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module) when you request a maintainer to cut a new release (Devolutions Gateway, Devolutions Agent, Jetsocat, PowerShell module)

• Add the label release-blocker Follow-up is required before cutting a new release if a follow-up is required before cutting a new release

• Add the label publish-required Please publish libraries (`Devolutions.Gateway.Utils`, OpenAPI clients, etc) when you request a maintainer to publish libraries (Devolutions.Gateway.Utils, OpenAPI clients, etc.)

• Add the label publish-blocker Follow-up is required before publishing libraries if a follow-up is required before publishing libraries