Remove windows-2019 pipeline image

[dan-hughes]

Pull Request (PR) description

Windows 2019 pipeline image is going to be deprecated on 30/06/2025.

This Pull Request (PR) fixes the following issues

• Fixes Remove windows-2019 pipeline image #26

Task list

• Added an entry to the change log under the Unreleased section of the
  file CHANGELOG.md. Entry should say what was changed and how that
  affects users (if applicable), and reference the issue being resolved
  (if applicable).
• Resource documentation added/updated in README.md.
• Resource parameter descriptions added/updated in README.md, schema.mof
  and comment-based help.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated. See DSC Community Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[johlju]

Reviewed 8 of 8 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @dan-hughes)