Fix Code.astro shiki css class replace logic (#5829)

Author: giuseppelt

.changeset/sweet-rocks-count.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix `Code.astro` shiki css class replace logic

packages/astro/components/Code.astro

@@ -37,7 +37,7 @@ const { code, lang = 'plaintext', theme = 'github-dark', wrap = false } = Astro.
 /** Replace the shiki class name with a custom astro class name. */
 function repairShikiTheme(html: string): string {
 	// Replace "shiki" class naming with "astro"
-	html = html.replace('<pre class="shiki"', '<pre class="astro-code"');
+	html = html.replace(/<pre class="(.*?)shiki(.*?)"/, '<pre class="$1astro-code$2"');
 	// Handle code wrapping
 	// if wrap=null, do nothing.
 	if (wrap === false) {