[JENKINS-62317]: Upgrade dependencies pre 2.3 release

[kinow]

Using git-plugin as reference. One major issue is that the build is failing due to hamcrest dependency, coming from powermock.

I think we will need to update to JUnit5, and replace Powermock with... mockito maybe.

[kinow]

Build passing locally now. Pending:

• smoke test with some builds
• check if there's any obvious issue for users upgrading their installations
• create ticket or add to release notes (or both)

[kinow]

Smoke tests look good.

[kinow]

Issue created, commits re-worded. https://issues.jenkins-ci.org/browse/JENKINS-62317

[kinow]

check if there's any obvious issue for users upgrading their installations

Tested the following:

• Installed latest LTS 2.222.3
• Installed recommended plugins
• Tested one job with active choices parameter, and another reactive parameter (state & city example from wiki)
• Installed Scriptler
• Moved City parameter script to groovy

Everything worked fine.

• Installed the package created from this branch with mvn package. It appeared on the list of plug-ins as 2.3-SNAPSHOT
• Loaded existing job with no warnings/exceptions
• Executed job again, no issues
• Loaded previous builds and accessed parameter info
• Modified job to have a third dynamic reference parameter
• Looks good to me, 🏁 ✔️