The SkinGetPoweredBy hook was deprecated in 1.37
It's also added as a variable inside SkinTemplate like so:
// Run deprecated hook. $this->getHookRunner()->onSkinGetPoweredBy( $poweredBy, $this ); $tpl->set( 'poweredbyico', $poweredBy ); $tpl->deprecate( 'poweredbyico', '1.37' ); // [[phab:T290583]] # acceptance criteria [] remove the code [] add to RELEASE NOTES under breaking change
Usages are non-existent and less likely given T305560 so let's remove: