Use OpenJDK 25 for running Gerrit

The container images failed to build for Gerrit on
master branch.

This also required an update of Alpine to 3.23.4.

Change-Id: Ic3e47bdf6453be181d9df25ad43abba3f418df99

container-images/base/Dockerfile

diff --git a/container-images/base/Dockerfile b/container-images/base/Dockerfile
index b3b2c30..48f4aae 100644
--- a/container-images/base/Dockerfile
+++ b/container-images/base/Dockerfile
@@ -1,4 +1,4 @@
-ARG BASE_IMAGE=alpine:3.21.3
+ARG BASE_IMAGE=alpine:3.23.4
 FROM $BASE_IMAGE
 
 ENV LC_ALL=C.UTF-8

container-images/gerrit-base/Dockerfile

diff --git a/container-images/gerrit-base/Dockerfile b/container-images/gerrit-base/Dockerfile
index 6eb2fc9..eec00cc 100644
--- a/container-images/gerrit-base/Dockerfile
+++ b/container-images/gerrit-base/Dockerfile
@@ -6,7 +6,7 @@
       coreutils \
       curl \
       openssh-keygen \
-      openjdk21
+      openjdk25
 
 RUN mkdir -p /var/gerrit/bin && \
     mkdir -p /var/gerrit/etc && \