Add certutil to Ubuntu

[lawrencegripper]

Description

New tool

Adds certutil via libnss3-tools from apt

This significantly simplifies certificate handling when working with playwright in CCA

• https://launchpad.net/ubuntu/focal/+package/libnss3-tools.

Related issue:

Check list

• Related issue / work item is attached
• Tests are written (if applicable)
• Documentation is updated (if applicable)
• Changes are tested and related VM images are successfully generated

[lawrencegripper]

Giving CI a run now, think I have this setup right but lets check

[Copilot]

Pull Request Overview

This PR adds the certutil command-line tool to Ubuntu toolsets by installing the libnss3-tools package, which simplifies certificate handling when working with Playwright in CCA environments.

• Adds libnss3-tools package to Ubuntu 22.04 and 24.04 toolset configurations
• Updates test configuration to verify certutil command availability from the libnss3-tools package

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
images/ubuntu/toolsets/toolset-2404.json	Adds libnss3-tools to Ubuntu 24.04 package list
images/ubuntu/toolsets/toolset-2204.json	Adds libnss3-tools to Ubuntu 22.04 package list
images/ubuntu/scripts/tests/Apt.Tests.ps1	Maps libnss3-tools package to certutil command for testing

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