Trigger CRD docs automation on new releases rather than pushes to main

[JakeSCahill]

This pull request includes updates to the .github/workflows/dispatch-crd-docs.yml file to change the workflow trigger so that docs are updated upon each release.

Changes to workflow trigger:

• Updated the trigger from a push to the main branch to a release event of the type 'published'. This change ensures the workflow runs when a new release is published instead of on every push to the main branch.

Related PR: redpanda-data/docs#1024

[chrisseto]

I rebased this onto main, CI should pass now.

[github-actions]

This PR is stale because it has been open 5 days with no activity. Remove stale label or comment or this will be closed in 5 days.