Auto-dispatch helm release on successful image publish

[bschwedler]

Summary

After a production image build succeeds on main, dispatch rstudio/helm's product-release.yml workflow so the corresponding Helm chart's image.tag is bumped automatically instead of by hand.

Each image repo generates a token via its product-team GitHub App and calls gh workflow run product-release.yml --repo rstudio/helm --field product=<name> --field version=<app-version>.

PRs (from #302)

• Add product-release workflow dispatch rstudio/helm#830
• Add update-helm job to production workflow images-connect#59
• Add update-helm job to production workflow images-workbench#65
• Add update-helm job to production workflow images-package-manager#63

Dependencies

• GitHub App installs (via rstudio/github-iac): posit-connect-projects, workbench-ide-release, posit-package-manager-automation must be installed on rstudio/helm with actions: write.