ci: rebuild and deploy the demo app

[ColinFay]

User - Validation

• [ ] The repo up to date at https://github.com/ThinkR-open/golemmetrics
• [ ] The app is avaiable and up to date at The app is avaiable and up to date at https://github.com/ThinkR-open/golemmetrics

Dev - Tech

Rebuild the man test in CI

Estimated time

01h00.

• [ ] When I close this issue, devtools::check() is 0 0 0
• [ ] When I close the issue, I've written the time spent solving this issue, using /spent