* ci-cd#754:Fix slow unit tests

 - Add nextest config
 - Add slow tests to mutual exclusion list

* Update .config/nextest.toml

Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>

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Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>