Install java in the docker image (#4399)

Java is used to run jing, to explain schema violations

Author: arnaud-lb

.docker/Dockerfile

@@ -1,7 +1,7 @@
 FROM php:8.2-cli
 
 RUN apt-get update && \
-    apt-get install -y git
+    apt-get install -y git default-jre-headless
 
 WORKDIR /var/www