Allow use of localhost registry for limited testing

Limited testing is permitted within the EULA using private
images so long as they are published to a registry on localhost.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Update Go to 1.23 and vendored dependencies

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Clarify EULA application since 2019

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>