Remove deprecated extended-choice-parameter plugin integration

[timja]

• see [JENKINS-72981] Remove Commons Lang 2 from core jenkins#16404

As part of the commons-lang2 to commons-lang3 migration I've noticed that this plugin is shipping a deprecated test dependency.

Do we need this support?

Ideally we shouldn't be adding support for plugins that are not recommended for use and have been end of lifed.

cc @topikachu it was added in #124

Its causing a failure in jenkinsci/bom#6234

Testing done

Submitter checklist

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[timja]

Possible to 🚢 @olamy?