Can i detach a guardian angel attached on an enemy Green akali and attach to an enemy scuttle if i use angle shot even if akali is not in combat?

Yes — you can, because Angle Shot never chooses Akali.

Angle Shot has you choose a unit and an Equipment with the same controller, then attach or detach. Choosing the enemy Scuttle Crab (any legal unit of the Angel's controller) plus the Guardian Angel itself is enough — the Gear is a valid target even while attached (FAQ #3302), and moving an already-attached Equipment onto a different unit is explicitly allowed (FAQ #6189). Akali is never chosen by the spell, so her "I can't be chosen by enemy spells or abilities unless I'm in combat" passive (Akali, Silent, Calm) never comes up, and it doesn't matter that she isn't in combat.

The distinction matters: if you instead tried the detach mode by choosing Akali as the unit, the spell would be blocked — that's the Ruin Runner case in FAQ #9110, where detaching an Equipment from an untargetable unit fails because the spell must choose it (Rule 758). The attach mode just needs a different unit of the same controller to exist as a legal choice. Note the Angel's effect text and +1 Might go with it, leaving Akali clean.