[codex] Support dispatched API generation

[mzanoni]

Summary

• Add an optional dispatch-id input to the API generation workflow.
• Use the dispatch id in run-name so callers can reliably find and watch the exact workflow run they triggered.
• Preserve the existing workflow updates on this branch for resolving the next Maven package version.

Validation

• Parsed edited workflow YAML files with Ruby YAML.load_file.
• Ran git diff --check; only existing line-ending normalization warnings were reported.

Note

• The local src/pom.xml change was left unstaged and is not part of this PR.

[mzanoni]

Closing this because the caller no longer needs to correlate or wait for target workflow runs. The existing workflow_dispatch input is enough for fire-and-forget dispatch.