In a scenario where `$input-line-height` or `$input-font-size` are different than `$input-btn-line-height` and `$input-btn-font-size` the final `$input-height-inner` was wrongly calculated.

* Add variable for dropdown-divider-margin-y

For us to reassign the nav-divider-margin-y variable here, we have to rearrange some of the variables.

Fixes #26660.

* bump bundlesize

Fixes #26465

Fixes #27595

* Tweak the accessibility/reduced motion text

include mention of carousel slides, remove the (now inaccurate, as Firefox 63 includes it too) mention that support is limited to Safari/macOS

xref https://github.com/twbs/bootstrap/issues/27525

* Add new callout for reduced motion

* Add variable to control prefers-reduced-motion media query support

* Add callout about prefers-reduced-motion to all components currently using animation which are affected