Some slotProps properties (e.g., inputLabel) are not supported

[metalmarker]

MuiTelInput is relying on TextField, which deprecated some props in MUI 6 (e.g., InputProps, inputProps, InputLabelProps, etc) in favor of slotProps. MuiTelInput is using slotProps internally, and is including slotProps.htmlInput and slotProps.input, however other slotProps (e.g., inputLabel) will be ignored.

A temporary workaround is use the deprecated props (e.g., InputLabelProps), however support will be removed in MUI 7.

I propose that MuiTeInput will use @mui/material/utils/mergeSlotProps internally to merge all provided slotProps properties to resolve this issue and maintain full compatibility with slotProps now and in the future.