[core] Remove unnecessary usages of useEventCallback

[NMinhNguyen]

• I have followed (at least) the PR section of the contributing guide.

It's best to review this PR without whitespace changes.

I've removed references to useEventCallback where as far as I can tell, there would be no difference from the way it's currently used:

• in useButton, it was applied to functions that would create event handlers, but then these "factory" functions are called inside this file, so there's no need to maintain a stable reference to them. I've also added a create prefix to them to match the naming convention used in https://github.com/mui-org/material-ui/blob/e0cdcd130db60d252c4382570844ea7278649a08/packages/mui-material/src/ClickAwayListener/ClickAwayListener.tsx#L149 for clarity.
• in useSwitch again the functions were not passed outside of the hook and only called inside this file, so there's no point in maintaining a stable reference
• in SliderUnstyled the event handlers that I've removed it from, were passed directly to <input> and React doesn't require them to have a stable reference: https://twitter.com/dan_abramov/status/1102708434821173249

[mui-pr-bot]

Details of bundle changes

Generated by 🚫 dangerJS against 460a21f

[mnajdova]

in SliderUnstyled the event handlers that I've removed it from, were passed directly to and React doesn't require them to have a stable reference: https://twitter.com/dan_abramov/status/1102708434821173249

Nice 👍

[mnajdova]

Nice! All changes make sense to me. Thanks for looking into this 🙏

[NMinhNguyen]

Thank you @mnajdova!

[michaldudak]

Thanks for taking care of this!