fix bug horizontal scroll when hiddenDates are present

[wesetaca]

Thank you for the library - helped me greatly with my angular ERP project, and I thought I should contribute with what I could. While working with the library I noticed that scrolling with the following config (partial) - the horizontal scroll behaves unpredictably when hitting hiddenDates boundaries or with those boundaries present: hiddenDates: [ { start: new Date('2025-08-01T15:00:00.000Z'), end: new Date('2025-08-02T01:00:00.000Z'), repeat: 'daily' }, ], verticalScroll: true, horizontalScroll: true, horizontalScrollKey: 'shiftKey', horizontalScrollInvert: true,

Through a lot of trial and error with console.log, I found the bug was due to the partially developed onMouseWheel (onDrag works fine though so I replicated some of onDrag logic). This fix was adapted from my monkey-patch of my angular project (I ended up hijacking the mouse wheel back when simultaneous horizontal and vertical Scroll was not supported) - and it is my first time contributing, so excuse me if there's any mistake.

I can attach/email my original fix should you find this adaptation faulty and want the original monkey-patch.