Update dependency postcss to ^8.5.5 (#444)

| datasource | package | from  | to    |
| ---------- | ------- | ----- | ----- |
| npm        | postcss | 8.5.4 | 8.5.5 |

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -9,7 +9,7 @@
         "@tailwindcss/typography": "^0.5.16",
         "autoprefixer": "^10.4.21",
         "laravel-mix": "^6.0.49",
-        "postcss": "^8.5.4",
+        "postcss": "^8.5.5",
         "tailwindcss": "^3.4.17"
     },
     "dependencies": {