Fix #5196: use precise sha1 instead of deleted tag vm-20.3.0

[sdedic]

It seems that graalvm project deleted the tag we'd relied on, so I've just replaced the tag name with the tag's sha1 commit id. Since it is not possible to git clone a specific commit, I've used an alternative technique to avoid full (big) clone -- see for example https://www.techiedelight.com/clone-git-repository-with-specific-revision/

It will be eventually better to upgrade to newer graal / mx sources.

[mbien]

looks good!

[mbien]

lets get this in so that the tests can run again.

technically master would be red right now but the mx test step is ignored on master since it fails so often despite retry script. It is only required to pass on PRs, as you can see on the conditional continue-on-error:

netbeans/.github/workflows/main.yml

Lines 714 to 717 in 9ea17f3

	# run unreliable steps first to fail early
	- name: java/java.mx.project
	continue-on-error: ${{ github.event_name != 'pull_request' }}
	run: .github/retry.sh ant $OPTS -f java/java.mx.project test

[jtulach]

It will be eventually better to upgrade to newer graal / mx sources.

That's certainly the idea! Yes, please move the testing to (at least) 22.3 version to make sure NetBeans/VSCode supports the latest GraalVM sources! CCing @MartinBalin

Btw. there shall be (and certainly used to be) a gate in GraalVM CI verifying that the latest stable version of NetBeans/IGV supports the latest GraalVM sources. As far as I know the gate was disabled in Dec 2021 when support for JDK8 was dropped. Consider re-establishing that gate, @sdedic

[mbien]

does this have to build graal from source? This is currently sidelining the CI cache, but graal src+bin would be also a bit too large to put into the cache so there is probably no way around it right now - just curious.