Update CI to account for upstream ci changes

[nfuden]

Upstream has had some amazing work done on its ci in 1.26

This put us in an unenviable space where we had to change our envoy-gloo release process from relying on the upstream do_ci.

Our current work around is to checkout 1.25 to use that ci script as our base.

In this issue we MUST decide if we are to move off from upstream do_ci or to update our ci to work with the new upstream ci scripts.

This MAY include putting up prs for envoy that may only be in 1.27+ but we shouldnt rely on this checkout strategy for the long time.