Update version of Java used during release to match what is installed on tern.

Author: smillst

build.gradle

@@ -397,6 +397,8 @@ allprojects { currentProj ->
     // Add standard javac options
     tasks.withType(JavaCompile) { compilationTask ->
       dependsOn(':installGitHooks')
+      // Use JDK 21 because that is what used in the release.  If you update this line, also update,
+      // JAVA_HOME in docs/developer/release/release_vars.py.
       boolean jdk21Compiler = project.getProperties().getOrDefault('useJdk21Compiler', false)
       if (jdk21Compiler) {
         // This uses the Java 21 compiler to compile all code.

docs/developer/release/release_vars.py

@@ -154,8 +154,8 @@ def execute(command_args, halt_if_fail=True, capture_output=False, working_dir=N
 os.environ["TEXINPUTS"] = ".:/homes/gws/mernst/tex/sty:/homes/gws/mernst/tex:..:"
 os.environ["PERLLIB"] = getAndAppend("PERLLIB", ":") + perl_libs
 os.environ["PERL5LIB"] = getAndAppend("PERL5LIB", ":") + perl_libs
-os.environ["JAVA_17_HOME"] = "/usr/lib/jvm/java-17-openjdk/"
-os.environ["JAVA_HOME"] = os.environ["JAVA_17_HOME"]
+os.environ["JAVA_21_HOME"] = "/usr/lib/jvm/java-21-openjdk/"
+os.environ["JAVA_HOME"] = os.environ["JAVA_21_HOME"]
 
 EDITOR = os.getenv("EDITOR")
 if EDITOR is None: