Autoprefixer and PostCSS calc not generating proper IE11 grid syntax when repeat() function contains calc()

This is really obscure, but easy enough to fix. Throwing this in Olivero, since that's the only place in core that uses IE CSS Grid syntax.

The problem is that the combination of autoprefixer and PostCSS Calc is generating invalid IE compatible grid syntax. But... it only does that when there's a calc() function nested inside a repeat() function.

From the following source code:

grid-template-columns: repeat(calc(var(--grid-col-count--md) - 2), minmax(0, 1fr));

It will generate the following invalid IE compatible CSS

-ms-grid-columns: (minmax(0, 1fr))10]

The problem with the above code is that it's missing a beginning square bracket [ before the last number (10).

It should be

-ms-grid-columns: (minmax(0, 1fr))[10]

I'm honestly not sure in which plugin the problem lies. I've searched GitHub issues and came up empty. I think the easiest fix is to manually enter in the CSS grid syntax where necessary.