[release/6.0] Convert to 1ES templates (#54656)

* Convert to 1ES templates

* Fix

* For real this time

* Fix pools

* Remove duplicate

* Cleanup

* Update-eol-versions-6.0 (#54784)

* Update EOL versions

* Update eng/targets/Helix.Common.props

Co-authored-by: William Godbe <[email protected]>

* Update eng/targets/Helix.Common.props

* Update eng/targets/Helix.Common.props

* Update eng/targets/Helix.Common.props

* Update Alpine and Mariner versions

* Remove changes to common files

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Co-authored-by: William Godbe <[email protected]>

* Update ci-public.yml

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Co-authored-by: Rich Lander <[email protected]>

Author: wtgodbe