Add workflow dispatch to workflow

[ShotaAk]

What does this implement/fix?

GitHub workflowを手動実行できるように、workflow_dispatchを追加します。

Does this close any currently open issues?

いいえ

How has this been tested?

CI設定変更のため、実機検証不要です。

いくつかのworkflowで失敗しますが、こちらは別PRで対応します。

Checklists

• [x] I have read the CONTRIBUTING guidelines.
  • If there is no guideline in the repository, rt-net organization's guideline applies.
• [x] I have checked to ensure there aren't other open Pull Requests for the same change.