chore(deps): update dependency postcss7 to v8

[skip netlify]

Author: renovate[bot]

package.json

@@ -91,7 +91,7 @@
     "pkg-types": "^1.3.0",
     "postcss": "^8.4.49",
     "postcss-loader": "^8.1.1",
-    "postcss7": "npm:postcss@7",
+    "postcss7": "npm:postcss@8",
     "prettier": "^3.4.2",
     "rimraf": "^6.0.1",
     "rollup": "^4.29.1",