Integrating manage currency v2 workflow

[pkalligudda-ibm]

The GitHub Actions only reads workflow files from the default branch of a repository (which is master here) when a workflow_dispatch trigger is used. Even though the v2 work was developed on the v2-migration branch, the currency-build-v2.yaml file must exist in master for GitHub to:

• Show it in the UI — the "Run workflow" button in the Actions tab only appears for workflows defined on the default branch.
• Allow manual dispatch — workflow_dispatch events are only registered from the default branch; triggering from any other branch requires the file to already be present there.
• Reference scripts correctly — the workflow's uses: steps and script paths (gha-script/v2-script/…) are checked out from whichever ref the job runs on; having the YAML in master ensures all referenced scripts are co-located and versioned together.