cmake(ci): cleanup docker

Author: Mizux

cmake/docker/alpine/java.Dockerfile

@@ -1,7 +1,7 @@
 FROM ortools/cmake:alpine_swig AS env
 
-ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 RUN apk add --no-cache openjdk21 maven
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 FROM env AS devel
 WORKDIR /home/project