feat: simulate "trigger workflows when new version available on npm"

[tbouffard]

This simulates what we are achieving in the bpmn-visualization repository. Introduce a workflow that sends a repository-dispatch event which triggers the workflow that builds the bpmn-visualization demo for the repository of examples.

Additional refactoring

• simplify the retrieval of inputs of a workflow_dispatch
• bump peter-evans/repository-dispatch from v2 to v3 (mainly to enforce run with Node20) in the shared action

Covers process-analytics/bpmn-visualization-js#2864

[tbouffard]

Merging as the new workflow can only be triggered manually once available in the default branch.
Testing will follow.

[tbouffard]

✔️ Tests successful

Running the "simultate npm publish" workflow and validate that the chain of events is triggered

With a version related to a tag that doesn't exist (12.0.4)

• 1st run ko, error in the workflow file https://github.com/process-analytics/github-actions-playground/actions/runs/10580448530
• fixed with fix: clean syntax when sending repository_dispatch #374
• 2nd run with the branch of PR fix: clean syntax when sending repository_dispatch #374 OK https://github.com/process-analytics/github-actions-playground/actions/runs/10580546664/job/29315686047 --> the run fails because the tag doesn't exist

With a version related to a tag that exists (3.0.3)

• https://github.com/process-analytics/github-actions-playground/actions/runs/10580620253