Update the shared gateway default_image, Helm chart values, the standalone
Kubernetes manifest, and the dev gateway task scripts to use
docker.io/library/alpine:3.22 instead of the community base image, consistent
with default_sandbox_image(). GPU e2e image-build base is left unchanged (CUDA
needs a glibc base).
Part of #3116.
Signed-off-by: Akram
Signed-off-by: Akram <akram.benaissi@gmail.com>