[Bug]: User Warning during boxplot creation (FixedFormatter)

[myrmarachne]

Environment

- QF-LIB: 3.0.0
- Python: 3.11

What happened?

Creation of boxplots raises the following User Warning:

UserWarning: FixedFormatter should only be used together with FixedLocator
  axis.set_ticklabels(self._labels, ha="right", rotation_mode='anchor')

Screenshots

No response

Reproduction steps

1. Run the return_quantiles_chart.py demo script and you can observe the warning.

Relevant log output

No response