search, update regen script from knowledgeagent to knowledgebase

[XiaofeiCao]

Description

• fix Increment versions for search releases #47314 (comment)
• Align with latest README.MD:

  azure-sdk-for-java/sdk/search/azure-search-documents/swagger/README.md

  Line 26 in edbe415

  package version, e.g. `--tag=searchindex`, `--tag=searchservice`, and `--tag=knowledgebase`.

• CI pass for patch release branch

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull request overview

This PR corrects a typo in the code generation script by updating the tag from 'knowledgeagent' to 'knowledgebase', aligning with the swagger README.md documentation.

Key Changes

• Updated the third Autorest tag in Update-Codegeneration.ps1 from '--tag=knowledgeagent' to '--tag=knowledgebase'