Update RAG DB with latest AAP 2.6 product docs

[TamiTakamiya]

For https://redhat.atlassian.net/browse/AAP-71099

Update RAG DB with latest AAP 2.6 product docs.

This PR also deletes:

• AAP 2.5 product docs, and
• Old scripts that are no longer used

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Note

Medium Risk
Primarily documentation/metadata churn, but the large content swap (including new sections and removed 2.5 docs) can impact downstream RAG indexing, anchors, and link targets if any consumers rely on the previous IDs/paths.

Overview
Updates the ansible_on_clouds/2.x plaintext documentation corpus, including Azure guide edits (anchor/title fixes, clearer procedures, and updated Microsoft Learn links) and new Azure sections such as policy remediation timeline and primary/business continuity regions.

Expands the AWS service-on-AWS docs with new content around deployment preparation and AWS PrivateLink (ingress/egress guidance, traffic control/IP restriction docs), plus additional metadata entries and corrected filenames.

Prunes legacy AAP 2.5 access_management_and_authentication plaintext/metadata content, and updates various cross-guide references from 2.5 to 2.6 URLs.

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