Update workflow references and playbook docs for private-repo restructure

[Crola1702]

Description

Companion PR to the workflow restructure in buildfarm-tools-private (https://github.com/osrf/buildfarm-tools-private/pull/107). No behavioral changes to this repo's own triage tooling, only removes a workflow whose logic moved to the private repo, and updates references/docs to match.

• Removes .github/workflows/dailyWorkflow.yml. The "close/open weekly buildfarmer-log issue, then post the triage report" logic it ran now lives in buildfarm-tools-private's publish-triage-issue.yml, chained after that repo's generate-core-data.yml.
• daily-workflow-ci.yml: drops the path-filter entry for the deleted dailyWorkflow.yml, since daily-workflow-ci.yml is now the only daily-workflow YAML file left in this repo.
• Renames greenness-reports-deploy.yml → deploy-reports-site.yml to match the verb-first naming adopted for the renamed workflows in buildfarm-tools-private.
• Updates playbook/buildfarmer/*.md (automation_workflows.md, add_new_gazebo_distribution.md, greenness_report.md, job_priorities.md, known_issues.md) to reference the new workflow names/locations and reflect that Gazebo dashboard generation is no longer a standalone workflow.
• Fixes "on pull requests touching ... or either daily-workflow YAML file" → singular in automation_workflows.md, matching the dailyWorkflow.yml removal above.