Simplify release steps and clean-up release process

[nightlark]

On a release checklist, there are a number of places that involve manual intervention: GMLC-TDC/HELICS#2509

Mainly, triggering most of the helics-packaging workflows could happen as part of updating the version file. There are some other parts that could be cleaned up.

• Migrate HELICS version update from repository_dispatch to workflow_dispatch trigger
• Add additional verification checks to HELICS release build workflow to verify that all artifacts were built successfully
• Add additional checks to version update workflow(s) in helics-packaging to verify success of various steps
• Consider using workflow_run to start package update as soon as the version file has been updated (maybe with a check to ensure no beta versions?)