build: update postcss to version 7.0.31

(cherry picked from commit 27d1200)

Author: renovate-bot

packages/angular_devkit/build_angular/package.json

@@ -43,7 +43,7 @@
     "open": "7.0.4",
     "parse5": "4.0.0",
     "pnp-webpack-plugin": "1.6.4",
-    "postcss": "7.0.30",
+    "postcss": "7.0.31",
     "postcss-import": "12.0.1",
     "postcss-loader": "3.0.0",
     "raw-loader": "4.0.1",

yarn.lock

@@ -9651,7 +9651,16 @@ postcss@7.0.27:
     source-map "^0.6.1"
     supports-color "^6.1.0"
 
-postcss@7.0.30, postcss@^7.0.30:
+postcss@7.0.31:
+  version "7.0.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.31.tgz#332af45cb73e26c0ee2614d7c7fb02dfcc2bd6dd"
+  integrity sha512-a937VDHE1ftkjk+8/7nj/mrjtmkn69xxzJgRETXdAUU+IgOYPQNJF17haGWbeDxSyk++HA14UA98FurvPyBJOA==
+  dependencies:
+    chalk "^2.4.2"
+    source-map "^0.6.1"
+    supports-color "^6.1.0"
+
+postcss@^7.0.30:
   version "7.0.30"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.30.tgz#cc9378beffe46a02cbc4506a0477d05fcea9a8e2"
   integrity sha512-nu/0m+NtIzoubO+xdAlwZl/u5S5vi/y6BCsoL8D+8IxsD3XvBS8X4YEADNIVXKVuQvduiucnRv+vPIqj56EGMQ==