fix: add missing Tailwind equivalent for `gl-flex-shrink-0`

What does this MR do?

It seems like gl-flex-shrink-0 actually is a proper Tailwind 3 util, otherwise it would not work at all in the product because we don't have it in the css_in_js.js. My understanding is that it's part of the deprecated utils that are being removed in Tailwind 4: https://tailwindcss.com/blog/tailwindcss-v4-alpha#whats-changed. So it's best we do add it to the equivalents to migrate to the newer syntax