Update dependency postcss to v8.5.12 (forgejo) (#12337)

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12337
Reviewed-by: Gusted <gusted@noreply.codeberg.org>

Author: viceice-bot

package-lock.json

@@ -58,7 +58,7 @@
     "mini-css-extract-plugin": "2.10.0",
     "minimatch": "10.2.5",
     "pdfobject": "2.3.0",
-    "postcss": "8.5.10",
+    "postcss": "8.5.12",
     "postcss-loader": "8.2.1",
     "postcss-nesting": "14.0.0",
     "pretty-ms": "9.0.0",