CI: more silence, remove deprecated check

What

Call make with --silent in sanity_ci..

Also remove a check in scripts/lint.sh.

Why

The option --silent makes logs more readable.

The check in lint.sh is redundant with CIAO.

How

Manually testing the MR

Check the job sanity_ci.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR