Docs: Suggestion; update "Color and background" note on color-contrast function

[coliff]

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

The 'Colors & background' page (https://getbootstrap.com/docs/5.3/helpers/color-background/#overview ) note at the top says:

"There’s currently no support for a CSS-native color-contrast function"

which was likely true at the time it was written, but perhaps that could be update to something like.

"There’s currently limited support for the contrast-color function"

with a link to: https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values/color_value/contrast-color

Motivation and context

Just a bit more context for this. Safari 26 and Firefox 146 both already support contrast-color(), hopefully Chrome/Edge will add support soon!