ci: Fix flink install on ARM64

[savex]

For ARM64 architecture JAVA_HOME env var is empty for some reason.
Flink installation expects it. Safety wise, no checking of arch, and extracting JAVA_HOME from java app itself if target var is empty

Fixes: redpanda-data/devprod#1015

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.3.x
• v23.2.x
• v23.1.x

Release Notes

• none

[savex]

/cdt
cdt_arch=arm64
rp_repo=nightly
rp_version=latest

[savex]

ARM64 build: https://buildkite.com/redpanda/redpanda/builds/43852

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/43848#018d18fa-d66b-4de0-867f-11862007392f

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/43848#018d18fa-d665-45db-a819-724d2a3b8703

[savex]

/cdt
cdt_arch=arm64

[gousteris]

/cdt
rp_repo=nightly
rp_version=latest
cdt_arch=arm64
ducktape_deps_git_version=15caae2c9fd9345cc98de9a898b774da76964f0d

[gousteris]

I see that cdt fails for nightly and ci packages.

• cdt-ci fails because there is no redpanda build in the https://buildkite.com/redpanda/redpanda/builds?branch=redpanda-data%3Adp-1015-fix-java-home-arm64 branch
• cdt-nightly fails to build the AMI because it pulls the ducktape deps from dev

I triggered cdt on nightly and set the ducktape deps version to the HEAD of this branch: https://buildkite.com/redpanda/redpanda/builds/43887

[gousteris]

Should we backport this to 23.3? the flink dependencies exist there https://github.com/redpanda-data/redpanda/blob/v23.3.x/tests/docker/ducktape-deps/flink

[savex]

Updated back port list

[vbotbuildovich]

/backport v23.3.x

[vbotbuildovich]

Failed to create a backport PR to v23.3.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-16135-v23.3.x-746 remotes/upstream/v23.3.x
git cherry-pick -x 15caae2c9fd9345cc98de9a898b774da76964f0d

Workflow run logs.