Cannot read properties of undefined (reading 'labels')

### Expected behavior

When calling generateLabels and passing the current Chart object as a parameter I would expect the generateLabels function to run.

### Current behavior

When running generateLabels with the Chart object passed as a parameter it fails with TypeError: Cannot read properties of undefined (reading 'labels').

When debugging the Doughnut controller overrides generateLabels function I can see we try to get the data from "chart.data" but this property doesn't exist. Hoever, the chart.chart.data exist.


### Reproducible sample

https://codesandbox.io/s/chartjs-error-legend-labels-dhmrtd

### Optional extra steps/info to reproduce

_No response_

### Possible solution

_No response_

### Context

I'm not able to show the legend label on my chart.

### chart.js version

4.3.0

### Browser name and version

_No response_

### Link to your project

_No response_