the restoring vm never resored when nova-compute restart

[xuyuanhao]

Description
===========
the restoring vms never be restored after nova-compute restart
Steps to reproduce
==================
1.soft delete the vms
2.execuate nova restore XXX to restore the instance.
3.down the nova-compute while restoring the vms.
4.restart the nova-compute
5.the instance.task_state is restoring
6.execuate nova restore XXX and restore the instance fail

Expected result
===============
the vm can restore success when restart the nova-compute

Actual result
=============
the vm task_state is restoring and can not restore anymore

Environment
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1. OpenStack Rocky version
2.Hypervisor is kvm
3.The storage is Ceph
4.Networking is Neutron with OpenVSwitch

Logs&Configs
============
The logs as following:
ERROR(conflict):Cannot 'restore' instance XXX while it is in task_state restoring