RDSC-5669 Publish RDI Cloud API reference

[ZdravkoDonev-redis]

THIS PR is still in DRAFT until we align on where exactly should the new RDI reference be - in a new page (like the current pR suggests) or in the sama page as the existing CAPI reference.

Summary

• add a Redis Cloud Data Integration API reference page backed by the CAPI RDI OpenAPI group
• update the Redis Cloud API sync workflow to fetch explicit capi and rdi grouped specs
• link the new Data Integration API reference from the Redis Cloud REST API landing page

Jira

https://redislabs.atlassian.net/browse/RDSC-5669

Replaces

#3561

Validation

• Verified deployed specs from api.redislabs.com: /v1/cloud-api-docs/rdi returns Data Integration Workspace API with 31 paths including /v1/data-integration-workspaces and /v1/subscriptions/{subscriptionId}/data-integration-workspace/rdi/api/v2/pipelines.
• Verified checked-in JSON with jq for title, tags, path count, and key RDI paths.
• Attempted Hugo render with hugo --logLevel warn --gc; it fails on an existing unrelated commands navigation template issue at content/commands/acl-list.md / layouts/commands/single.html.

[github-actions]

Staging links:
https://redis.io/docs/staging/rdsc-5669-rdi-capi-docs/operate/rc/api/
https://redis.io/docs/staging/rdsc-5669-rdi-capi-docs/operate/rc/api/data-integration-api-reference/

[CLAassistant]

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[jit-ci]

🛡️ Jit Security Scan Results

✅ No security findings were detected in this PR

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^{Security scan by Jit}