MINOR: Update release script for 4.0 (#18999)

This patch updates the release script to use JDK 21 to build the
release. We could also use JDK 17 but using JDK 21 directly does not
change much. We have to verify anyway that the server works with 17 and
the client with 11.

Reviewers: Ismael Juma <[email protected]>

release/release.py

@@ -127,14 +127,14 @@ def command_stage_docs():
     if not os.path.exists(kafka_site_repo_path) or not os.path.exists(os.path.join(kafka_site_repo_path, "powered-by.html")):
         fail("{kafka_site_repo_path} doesn't exist or does not appear to be the kafka-site repository")
 
-    jdk17_env = get_jdk(17)
+    jdk21_env = get_jdk(21)
 
     # We explicitly override the version of the project that we normally get from gradle.properties since we want to be
     # able to run this from a release branch where we made some updates, but the build would show an incorrect SNAPSHOT
     # version due to already having bumped the bugfix version number.
     gradle_version_override = detect_docs_release_version(project_version)
 
-    cmd("Building docs", f"./gradlew -Pversion={gradle_version_override} clean siteDocsTar aggregatedJavadoc", cwd=repo_dir, env=jdk17_env)
+    cmd("Building docs", f"./gradlew -Pversion={gradle_version_override} clean siteDocsTar aggregatedJavadoc", cwd=repo_dir, env=jdk21_env)
 
     docs_tar = os.path.join(repo_dir, "core", "build", "distributions", f"kafka_2.13-{gradle_version_override}-site-docs.tgz")
 
@@ -229,8 +229,7 @@ def verify_gpg_key():
 preferences.once(f"verify_gpg_key_{gpg_key_pass_id}", verify_gpg_key)
 
 apache_id = preferences.get('apache_id', lambda: prompt("Please enter your apache-id: "))
-jdk8_env = get_jdk(8)
-jdk17_env = get_jdk(17)
+jdk21_env = get_jdk(21)
 
 
 def verify_prerequeisites():
@@ -328,9 +327,9 @@ def delete_gitrefs():
 
 
 git.targz(rc_tag, f"kafka-{release_version}-src/", f"{artifacts_dir}/kafka-{release_version}-src.tgz")
-cmd("Building artifacts", "./gradlew clean && ./gradlew releaseTarGz -PscalaVersion=2.13", cwd=kafka_dir, env=jdk8_env, shell=True)
+cmd("Building artifacts", "./gradlew clean && ./gradlew releaseTarGz -PscalaVersion=2.13", cwd=kafka_dir, env=jdk21_env, shell=True)
 cmd("Copying artifacts", f"cp {kafka_dir}/core/build/distributions/* {artifacts_dir}", shell=True)
-cmd("Building docs", "./gradlew clean aggregatedJavadoc", cwd=kafka_dir, env=jdk17_env)
+cmd("Building docs", "./gradlew clean aggregatedJavadoc", cwd=kafka_dir, env=jdk21_env)
 cmd("Copying docs", f"cp -R {kafka_dir}/build/docs/javadoc {artifacts_dir}")
 
 for filename in os.listdir(artifacts_dir):
@@ -355,8 +354,8 @@ def delete_gitrefs():
 svn.commit_artifacts(rc_tag, artifacts_dir, work_dir)
 
 confirm_or_fail("Going to build and upload mvn artifacts based on these settings:\n" + textfiles.read(global_gradle_props) + '\nOK?')
-cmd("Building and uploading archives", "./gradlew publish -PscalaVersion=2.13", cwd=kafka_dir, env=jdk8_env, shell=True)
-cmd("Building and uploading archives", "mvn deploy -Pgpg-signing", cwd=os.path.join(kafka_dir, "streams/quickstart"), env=jdk8_env, shell=True)
+cmd("Building and uploading archives", "./gradlew publish -PscalaVersion=2.13", cwd=kafka_dir, env=jdk21_env, shell=True)
+cmd("Building and uploading archives", "mvn deploy -Pgpg-signing", cwd=os.path.join(kafka_dir, "streams/quickstart"), env=jdk21_env, shell=True)
 
 # TODO: Many of these suggested validation steps could be automated
 # and would help pre-validate a lot of the stuff voters test