Docs: Remove Kapa style overrides (#35642)

Removes unused styles for the Kapa.ai widget.

GitOrigin-RevId: c835a6034850d207384dfc9dd7706439ec34d73c

Author: mikewheaton

npm-packages/docs/src/components/ConvexAiChat/ConvexAiChat.tsx

@@ -1,7 +1,6 @@
 import React from "react";
 import { AIButton } from "../AIButton/AIButton";
 import Sparkle from "../AIButton/sparkle.svg";
-import "./kapa.css";
 
 export function ConvexAiChat() {
   return (