Pin GitVersion to v5 in pipeline and update templates

[johlju]

Pull Request

Pull Request (PR) description

Fixed

• Pinned GitVersion to v5 in the pipeline since v6 is not yet supported, also
  updated templates to pin GitVersion v5. Workaround for issue #477.

Task list

• The PR represents a single logical change. i.e. Cosmetic updates should go in different PRs.
• Added an entry under the Unreleased section of in the CHANGELOG.md as per format.
• Local clean build passes without issue or fail tests (build.ps1 -ResolveDependency).
• Documentation added/updated in README.md.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• 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 4 of 4 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @johlju)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81%. Comparing base (77d44e1) to head (0ecf19c).
Report is 5 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #479   +/-   ##
===================================
  Coverage    81%    81%           
===================================
  Files        44     44           
  Lines      2328   2328           
===================================
  Hits       1904   1904           
  Misses      424    424