PER-16379: remove the retired EU region from the docs - #659

Changed pages include:

• index.html - view
• 404.html - view
• faq/index.html - view
• permit-mcp-gateway/index.html - view
• quickstart/index.html - view
• status/index.html - view
• walkthroughs/index.html - view
• ai-security/framework/index.html - view
• api/api-reference/index.html - view
• api/api-with-cli/index.html - view

There are more changes not included in the list