mshv: remove CHK dependency from crash test

[vyadavmsft]

We do not need chk build anymore for crash.

[Copilot]

Pull request overview

This PR simplifies the MSHV root crash test by removing the requirement to provide and install CHK hypervisor binaries, and instead relying on the normal (FRE) environment while ensuring lockdown=integrity doesn’t block the crash trigger path.

Changes:

• Removes CHK binary/loader variables and the associated remote copy/extract/install flow.
• Adds logic to detect and remove lockdown=integrity from the dom0 boot configuration and reboot if needed.
• Cleans up imports accordingly.

[Copilot]

Pull request overview

This PR updates the MSHV root partition crash validation to no longer depend on providing external CHK hypervisor binaries, simplifying how the crash test is executed in the LISA MSHV test suite.

Changes:

• Removed CHK-binary copy/extract/installation flow and the associated required testcase variables.
• Updated the crash test flow to ensure lockdown=integrity is removed (via GRUB edit + reboot when needed) before triggering the hvdbg crash and validating kdump output.

[Copilot]

Pull request overview

This PR updates the MSHV root-partition crash validation to remove the dependency on external CHK hypervisor binary artifacts, and instead triggers the crash using the regular (FRE) hypervisor build after ensuring lockdown=integrity isn’t preventing access to the hvdbg debugfs trigger.

Changes:

• Removed CHK binary/loader copy & extraction flow (and associated test variables) from the crash test.
• Added logic to detect and remove lockdown=integrity from the dom0 GRUB config and reboot if needed before triggering hvdbg.
• Simplified imports and crash-test description to reflect the new approach.

[vyadavmsft]

@LiliDeng pls check