Revert "feat: load katex css in page content"

This reverts commit 20ff6c947e.

src/components/common/PageContent.tsx

@@ -1,4 +1,3 @@
-import "katex/dist/katex.min.css"
 import { type MutableRefObject, memo } from "react"
 
 import PostActions from "~/components/site/PostActions"

src/css/main.css

@@ -1,3 +1,5 @@
+@import url("https://fastly.jsdelivr.net/npm/katex@0.16.7/dist/katex.min.css");
+
 @import "./variables.css";
 @import "./tailwind.css";
 @import "./prose.css";