fix(deps): update @astrojs/tailwind to v6

Author: renovate[bot]

package.json

@@ -49,7 +49,7 @@
   "homepage": "https://www.gitify.io/",
   "dependencies": {
     "@astrojs/solid-js": "5.0.4",
-    "@astrojs/tailwind": "5.1.5",
+    "@astrojs/tailwind": "6.0.0",
     "@iconify-json/line-md": "1.2.5",
     "@iconify-json/mdi": "1.2.3",
     "@kobalte/core": "0.13.7",