MLE-23751 minor pipeline updates

[vitalykorolev]

Description

• add ML version to blackDuck parameters
• simplify timing and prioritizing ML12 in scheduled builds
• move timestamp in place of "nightly"
  OLD: 12.1.nightly-ubi-rootless-2.2.0-20250827
  NEW: 12.1.20250827-ubi-rootless-2.2.0

Checklist:

• Owner:

• JIRA_ID as part of branch/PR name

• Rebase the branch with upstream

• Squashed all commits into a single commit

• Added Tests

• Reviewer:

• Reviewed Tests

• Added to Release Wiki/Jira

[Copilot]

Pull Request Overview

This PR makes minor updates to the Jenkins pipeline configuration, focusing on improving Docker image tagging and adjusting build scheduling times.

• Refactored timestamped Docker tag creation to use a variable instead of inline concatenation
• Updated BlackDuck security scan parameters to include branch name and MarkLogic version
• Adjusted cron scheduling times for nightly builds across different MarkLogic versions

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