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