Update openjdk in CI image

Author: danrmiller

Dockerfile

@@ -20,7 +20,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
       ocl-icd-opencl-dev opencl-headers valac zlib1g-dev \
       g++-aarch64-linux-gnu gcc-aarch64-linux-gnu \
       g++-mingw-w64-x86-64 gcc-mingw-w64-x86-64 \
-      openjdk-17-jdk-headless \
+      openjdk-21-jdk-headless \
  && rm -rf /var/lib/apt/lists/*
 
 RUN curl -fsSL https://deb.nodesource.com/setup_24.x | bash - \