ci: run main CI checks on release branches too - #1740

Changed pages include:

• index.html - view
• 404.html - view
• blog/index.html - view
• docs/index.html - view
• testimonials/index.html - view
• docs/architecture/index.html - view
• docs/deployment/index.html - view
• docs/ssh-setup/index.html - view
• docs/upgrading-to-v2/index.html - view
• docs/user-manual/index.html - view

There are more changes not included in the list