fix(testing): reserve dev-server ports in the react-router e2e suite - #36585

Changed pages include:

• concepts/index.html - view
• enterprise/index.html - view
• extending-nx/index.html - view
• features/index.html - view
• getting-started/index.html - view
• guides/index.html - view
• how-nx-works/index.html - view
• platform-features/index.html - view
• plugin-registry/index.html - view
• reference/index.html - view

There are more changes not included in the list