* ENG-9585: Remove os templates

* add news

* remove more references

* Remove more template repo handling code

We don't need to enumerate templates for a release anymore, so this code can be
removed.

* remove more unused

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Co-authored-by: Masen Furer <m_github@0x26.net>
Co-authored-by: Farhan Ali Raza <62690310+FarhanAliRaza@users.noreply.github.com>