[deps]: Update @astrojs/tailwind to v6

Author: renovate[bot]

bun.lockb

@@ -12,7 +12,7 @@
   "dependencies": {
     "@astrojs/check": "0.9.4",
     "@astrojs/mdx": "4.0.3",
-    "@astrojs/tailwind": "5.1.4",
+    "@astrojs/tailwind": "6.0.2",
     "@fontsource/dm-sans": "5.1.0",
     "astro": "5.14.3",
     "astro-seo": "0.8.4",