Remove outdated note about requiring /root/.aws/credentials from Security Lake documentation

[ayodeko]

Description

Remove outdated note about requiring /root/.aws/credentials from Security Lake documentation

Documentation compilation

• Verified that documentation compiles without warnings.

Changelog

• Updated CHANGELOG.md.

Code formatting & web optimization

• Added or updated meta descriptions.
• Updated redirects.js if necessary (guide).
• Used three-space indentation in .rst files.

Writing style

• Used bold for UI elements, italics for key terms or emphasis, and code font for Bash commands, file names, REST paths, and code.
• Followed present tense, active voice, and a semi-formal tone.
• Wrote short, clear, and concise sentences.

[javimed]

While the issue mentions one specific note, the change involves updating documentation widely. For example, source/cloud-security/amazon/services/prerequisites/credentials.rst and other files.