Declare required jdk and maven as top-level pipeline tools in I-builds

[HannesWell]

Since eclipse-platform/eclipse.platform.swt#973 the I-build (like the SWT build) requires a java-17 (or later) jdk on the PATH system environment-variable in order to launch a jdk>=17 with the 'java' command from the CLI. Just setting the JAVA_HOME variable to a path pointing to a jdk-17 is not sufficient since the the java executable is usually located in $JAVA_HOME/bin. And while the maven launch script searches in $JAVA_HOME/bin for a java executable to run the build itself, a simple java command on the CLI isn't that smart.
Previously running the java command would just run the default default java version on the Jenkins executor.

In general this simplifies the build-configuration because the JDK to use is only defined once and used everywhere.

Hopefully fixes #1724. I have no way to test this in advance but the explanation above is the only one I found why the Maven build itself runs fine (which requires Java-17 because of Tycho), but fails as soon as a java command is launched that requires java>=17.

[akurtakov]

This is step in the right direction. Please merge and start new I-build so results are seen sooner.

[HannesWell]

This is step in the right direction. Please merge and start new I-build so results are seen sooner.

Done. Is there anything to do to synchronize the change in the groovy file with the actual job-configuration?
If I understand it correctly https://ci.eclipse.org/releng/job/Create%20Jobs/ does that? But it failed in the last two runs?

[HannesWell]

This is step in the right direction. Please merge and start new I-build so results are seen sooner.

Done. Is there anything to do to synchronize the change in the groovy file with the actual job-configuration? If I understand it correctly https://ci.eclipse.org/releng/job/Create%20Jobs/ does that? But it failed in the last two runs?

The error was: ERROR: You must configure the DSL job to run as a specific user in order to use the Groovy sandbox.
and it happened for all timer-based executions.
The one manually started by @MohananRahul succeeded so I assumed it only works if a user explicitly triggers the job and just triggered it too. The run succeed and looking at the config of https://ci.eclipse.org/releng/job/Builds/job/I-build-4.31/ now it looks like this change was successfully applied.
I just triggered I-build-4.31#92 to verify it.

[HannesWell]

And while the maven launch script searches in $JAVA_HOME/bin for a java executable to run the build itself, a simple java command on the CLI isn't that smart.

For the record, that behavior of Maven is mentioned in the Maven Installation Guide.