[slider] onMouseDown function is not correctly updated

[zvakanaka]

🐛 Bug report

Current Behavior

Passing a useCallback function to the onMouseDown prop (and the other similar props) keeps the original function around.

Expected behavior

A useCallback function passed to the onMouseDown prop (and other similar props) should be updated when something in the dependency array changes.

Reproducible example

Sample of the issue in CodeSandbox

Your environment

Software	Name(s)	Version
Reach Package	@reach/slider	0.13.0
React	react	17.0.1
Browser	Firefox	86.0
Assistive tech	None	None
Node	node	v14.13.1
npm/yarn	yarn	1.21.1
Operating System	macOS	10.15.7

[chaance]

Good catch -- we're probably trying to be a little too clever here since by trying to avoid re-renders internally. That should probably be left to the user in this case. I've patched this up in a sandbox but am anticipating that you might have another problem unless you're trying to get the previous value in your event handler. Haven't merged anything yet because I need to test a few edge cases with these changes: https://codesandbox.io/s/intelligent-ives-0x6rz?file=/src/App.js

[chaance]

A note for self: this change will affect all pointer-related events, and we'll want to add notes in the documentation if users want to opt-in to the current behavior after the change.