[FEATURE] Update `prod_index_dump.yml` and `staging_index_dump.yml` workflow parameters

[adambuttrick]

Context

The indexing workflows tell the ROR API to download and index a data dump. They currently pass a data-env parameter that tells the API which GitHub repo to download the dump from (ror-data or ror-data-test). These workflows need to be updated in tandem with the ROR API changes so the API can locate the dump in the new release artifact location on ror-records.

Current behavior

• Both workflows take inputs: release-dump (filename without .zip), schema-version (v2), data-env (test/prod)
• They call index_dump.py, which constructs a URL as {api_url}/{filename}/{dataenv} and makes a GET request
• The data-env parameter tells the ror-api which GitHub repo to download the dump from (ror-data or ror-data-test)
• prod_index_dump.yml calls INDEX_DUMP_PROD_API_URL_V2
• staging_index_dump.yml calls INDEX_DUMP_STAGING_API_URL_V2

Proposed changes

The exact changes depend on how the ror-api sub-issue as part of the same epic (#355) resolves the dataenv parameter question:

• If ror-api adds a release-tag parameter: update index_dump.py and both workflows to pass the release tag instead of (or in addition to) data-env
• If ror-api keeps dataenv but changes its semantics: update workflow input descriptions to reflect the new meaning
• Update index_dump.py to construct the new URL format expected by the updated API endpoint
• Clean up workflow descriptions that reference "ror-data-test repo" and "ror-data" (lines 7, 17 in both files)

Files to modify

• .github/workflows/prod_index_dump.yml
• .github/workflows/staging_index_dump.yml
• .github/workflows/index_dump.py

Acceptance criteria

• index_dump.py constructs the correct URL format for the updated ror-api endpoint
• Workflow inputs and descriptions no longer reference the ror-data or ror-data-test repos
• Staging indexing workflow successfully triggers indexing from a release artifact
• Production indexing workflow successfully triggers indexing from a release artifact
• Both workflows remain compatible with the updated ror-api endpoint