fix: avm.res.virtual-machine-images.image-template upgrade common types to latest and update type to not nullable to fix failing static validation

[eriqua]

Description

Closes #3669

Managed identity was set to both nullable and Required parameter input. This fails a recently introduced Pester test checking for the correct parameter description and category. A required parameter cannot be nullable.
Hence removed the nullable property

Also updated common types utility module reference to latest

Pipeline Reference

Pipeline
(actually successful)

Type of Change

• Update to CI Environment or utilities (Non-module affecting changes)
• Azure Verified Module updates:
  • Bugfix containing backwards-compatible bug fixes, and I have NOT bumped the MAJOR or MINOR version in version.json:
    • Someone has opened a bug report issue, and I have included "Closes #{bug_report_issue_number}" in the PR description.
    • The bug was found by the module author, and no one has opened an issue to report it yet.
  • Feature update backwards compatible feature updates, and I have bumped the MINOR version in version.json.
  • Breaking changes and I have bumped the MAJOR version in version.json.
  • Update to documentation

Checklist

• I'm sure there are no other open Pull Requests for the same update/change
• I have run Set-AVMModule locally to generate the supporting module files.
• My corresponding pipelines / checks run clean and green without any errors or warnings

[microsoft-github-policy-service]

Important

The "Needs: Triage 🔍" label must be removed once the triage process is complete!

Tip

For additional guidance on how to triage this issue/PR, see the BRM Issue Triage documentation.

[microsoft-github-policy-service]

Important

If this is a module-related PR, being submitted by the sole owner of the module, the AVM core team must review and approve it (as module owners can't approve their own PRs).

To indicate this PR needs the core team''s attention, apply the "Needs: Core Team 🧞" label!

The core team will only review and approve PRs that have this label applied!