tests/docker: move alpine from edge to tagged release

Tracking alpine-edge like debian-sid is a moving target. Usually such
rolling releases are marked as "allow_failure: true" in our CI.
However as alpine presents a musl based distro and provides useful
extra coverage lets track a release branch instead to avoid random
breakages.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220929114231.583801-11-alex.bennee@linaro.org>

tests/docker/dockerfiles/alpine.docker

 # THIS FILE WAS AUTO-GENERATED
 #
-#  $ lcitool dockerfile --layers all alpine-edge qemu
+#  $ lcitool dockerfile --layers all alpine-316 qemu
 #
 # https://gitlab.com/libvirt/libvirt-ci
 
-FROM docker.io/library/alpine:edge
+FROM docker.io/library/alpine:3.16
 
 RUN apk update && \
     apk upgrade && \

tests/lcitool/refresh

@@ -107,7 +107,7 @@ try:
     #
     # Standard native builds
     #
-    generate_dockerfile("alpine", "alpine-edge")
+    generate_dockerfile("alpine", "alpine-316")
     generate_dockerfile("centos8", "centos-stream-8")
     generate_dockerfile("debian-amd64", "debian-11",
                         trailer="".join(debian11_extras))