Install CI/CD deps also on unit_test job

[misl6]

Maintainer merge checklist

• Title is descriptive/clear for inclusion in release notes.
• Applied a Component: xxx label.
• Applied the api-deprecation or api-break label.
• Applied the release-highlight label to be highlighted in release notes.
• Added to the milestone version it was merged into.
• Unittests are included in PR.
• Properly documented, including versionadded, versionchanged as needed.

Fixes an issue introduced via #8716 , as dependencies were not installed in unit_test job (coveralls is needed only on push to master)