ci: Output AIB release notes and cgmanifest to customization.log

[christinalau0]

Reason for Change:

• This is a temporary mitigation to get VHD release notes and cgmanifest.json during AIB VHD pipeline.
  • Note that when the image builder resource group is created, it must be manually locked so that the AIB customization.log and storage account will not be deleted by AIB pipeline after successful image creation.
  • In the future, we should add a proper step to copy out the VHD release notes and cgmanifest.json.
• Removed validation steps in release.yaml, these steps should be done by ADO pipelines (test vhd no egress and PR E2E) before triggering release.yaml.

Issue Fixed:

Credit Where Due:

Does this change contain code from or inspired by another project?

• No
• Yes

If "Yes," did you notify that project's maintainers and provide attribution?

• No
• Yes

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

[christinalau0]

Validated with ADO AIB pipeline.

[JesusAlvarezTorres]

lgtm