Adapt to New credentials dialog (don't merge)

[timja]

jenkinsci/credentials-plugin#992

Testing done

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[timja]

Ready for review but credentials plugin will need merging first: jenkinsci/credentials-plugin#992

[jtnord]

All seems reasonable, marking as draft to prevent accidental merging until we are ready

[jtnord]

needs to be reverted before merge

Suggested change

	<artifactItem>
	<groupId>org.jenkins-ci.plugins</groupId>
	<artifactId>credentials</artifactId>
	<version>1578.v4ea_f41d464ed</version>
	<type>hpi</type>
	</artifactItem>

[jtnord]

Needs to be reverted before merge

Suggested change

	<environmentVariables>
	<!-- Use local version of the plugin over the released one ATH would otherwise use -->
	<LOCAL_JARS>target/credentials.hpi</LOCAL_JARS>
	</environmentVariables>