Add JDK 23 to matrix

[SethTisue]

early access builds of 23 are already available

regardless, this can wait for a while

[SethTisue]

according to https://openjdk.org/projects/jdk/23/ ,

so now would probably be a good time

[SethTisue]

I don't think we have the disk space (either the gigabytes, or the inodes) to add JDK 23 without dropping 22 (or some other version), but I think dropping 22 is actually okay. fyi @lrytz

[SethTisue]

• behemoth 1
• behemoth 2
• behemoth 3

steps

• cd /usr/lib/jvm
• sudo curl -O -L 'https://download.java.net/java/early_access/jdk23/35/GPL/openjdk-23-ea+35_linux-x64_bin.tar.gz'
• sudo dtrx -n openjdk-23-ea+35_linux-x64_bin.tar.gz
• sudo rm openjdk-23-ea+35_linux-x64_bin.tar.gz
• sudo chmod -R go+rX openjdk-23-ea+35_linux-x64_bin
• sudo ln -s openjdk-23-ea+35_linux-x64_bin/jdk-23 java-23-openjdk-x64
• ./java-23-openjdk-x64/bin/java -version

openjdk version "23-ea" 2024-09-17
OpenJDK Runtime Environment (build 23-ea+35-2364)
OpenJDK 64-Bit Server VM (build 23-ea+35-2364, mixed mode, sharing)

and then

• make the jobs in Jenkins (by cloning)
• trigger runs
• verify the 2.12.x job picks up the right Java version
  • https://scala-ci.typesafe.com/job/scala-2.12.x-jdk23-integrate-community-build/
• verify the 2.12.x job is green
  • https://scala-ci.typesafe.com/job/scala-2.12.x-jdk23-integrate-community-build/
• verify the 2.13.x job picks up the right Java version
  • https://scala-ci.typesafe.com/job/scala-2.13.x-jdk23-integrate-community-build/
• verify the 2.13.x job is green
  • https://scala-ci.typesafe.com/job/scala-2.13.x-jdk23-integrate-community-build/
• disable the old JDK 22 jobs
  • including making sure the workspace directories are entirely gone

[SethTisue]

JDK 23 jobs are green. (Some projects fail for expected reasons, typically that they use a bytecode processor that needs upgrading, or they run into an important conflict involving java.io.IO which is new in 23.)

I disabled the JDK 22 jobs but did not outright delete them. Out of some perhaps not entirely rational general sense of caution. We can always delete them later.