fix: follow up from refactoring !17

!17 (diffs)

must be
response = self._tgsearch.list_project_root(self._project_id, self._sid)

assigned to @hynek

created branch 28-fix-follow-up-from-refactoring-17 to address this issue

mentioned in merge request !18 (merged)

mentioned in commit 605c2adb

closed with merge request !18 (merged)