[backport v1.2] [ENHANCEMENT] Take advantage of the attach/detach mechanism in Longhorn v1.5+

[harvesterhci-io-github-bot]

backport the issue #4907

[harvesterhci-io-github-bot]

Pre Ready-For-Testing Checklist

• If labeled: require/HEP Has the Harvester Enhancement Proposal PR submitted?

• Where is the reproduce steps/test steps documented?
  The reproduce steps/test steps are at: refactor: remove mount logic in harvester #4910

• Is there a workaround for the issue? If so, where is it documented?

• Have the backend code been merged (harvester, harvester-installer, etc) (including backport-needed/*)?
  The PR is at: refactor: remove mount logic in harvester (backport #4910) #5854

• If labeled: area/ui Has the UI issue filed or ready to be merged?

• If labeled: require/doc, require/knowledge-base Has the necessary document PR submitted or merged?

• If NOT labeled: not-require/test-plan Has the e2e test plan been merged? Have QAs agreed on the automation test case? If only test case skeleton w/o implementation, have you created an implementation issue?

  • The automation skeleton PR is at:
  • The automation test case PR is at:

• If the fix introduces the code for backward compatibility Has a separate issue been filed with the label release/obsolete-compatibility?
  The compatibility issue is filed at: