Go 1.21 EOL

[samruddhikhandale]

Depends on the release of #1160

• Create a release (if necessary - which ensures images are up to date before deprecating )
• Open a PR
• Update templates (if necessary)
• Update [Tracking] Image support, deprecation / EOL dates #90
• Update Microsoft Artifact Registry docs

[gauravsaini04]

Had raised images pr #1180 - merged
Templates pr #282 - merged
MCR Docs pr #47526 - merged

[romeroj748-creator]

To proceed with the release, ensure #1160 (support for Go 1.23) is completed. Then create a release if needed, open a PR, update templates, revise the tracking issue #90, and update Microsoft Artifact Registry docs. Recent PRs have been merged successfully.