Operational Definition: 'Intelligence is the property measured by IQ.'
That is not a definition at all, really.
IQ is measured with various instruments that do not all agree. And those instruments are based upon specific theories of intelligence, which share some common aspects (e.g. thinking speed matters, not just the quality of the outcome; creative approaches are not essential, consistency is; etc.)
But if they all measured exactly the same thing, they would merge and we would stop having multiple competing versions. That is a goal. Defining the goal by the current state leaves one navigating without a compass.
The question whether the above operational definition is too broad
does not depend on whether what it actually measures is intelligence
This is not logically possible if you have defined the one to be what the other measures.
but rather something else, such as diligence or resilience.
Those are not necessarily 'something else'. Measures are interdependent. If what you measure has correlates or parts, then measuring it involves measuring those, too.
A science teases apart the right things to measure over time by seeing what measures are stable when others vary. It may be possible that there is no stable definition of 'resilience'. It may be that people are more or less resilient in different contexts, so things that depend upon resilience would do better to measure a number of other stable factors instead and predict the appearance to which we lend the informal label of 'resilient'. The resulting composite exists if we use the word, but it may be subjective or contingent and not a good measure.
If IQ tests are meant to be developed, compared, and chosen between, they must actually measure something. So then questions about what the contributing factors are to what is being measured cannot be irrelevant to whether the test is a good one.