test(all): substitude assert.Error by assert.ErrorContains

[gen2thomas]

Solved issues and/or description of the change

fix accidentally used assert.Error() (checks only for existing error, the text is used in case of fail) instead of assert.ErrorContains() (the text needs to be contained in the error)

Checklist

• The PR's target branch is 'hybridgroup:dev'
• New and existing unit tests pass locally with my changes (e.g. by run make test)
• No linter errors exist locally (e.g. by run make fmt_check)
• I have performed a self-review of my own code (no productive code is changed)