Culprit:
(1) - DirectiveGenerator/index.jelly#L81
(2) - DirectiveGenerator/index.jelly#L83-L108

Reproduction steps:

• Install Pipeline: Declarative
• Navigate to: [JENKINS_INSTANCE]/directive-generator/

Screenshot attached about where the feature is displayed.

Proposal
Culprit 1 - https://www.jenkins.io/doc/developer/security/csp/#inline-event-handlers
Culprit 2 - https://www.jenkins.io/doc/developer/security/csp/#inline-javascript-blocks

Testing notes
 - Ensure to reproduce the feature before any change
 - Ensure that you reproduce the feature after you have made the change