Bump postcss-nested from 4.1.2 to 4.2.1

Bumps [postcss-nested](https://github.com/postcss/postcss-nested) from 4.1.2 to 4.2.1.
- [Release notes](https://github.com/postcss/postcss-nested/releases)
- [Changelog](https://github.com/postcss/postcss-nested/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss-nested/compare/4.1.2...4.2.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

yarn.lock

@@ -8402,12 +8402,12 @@ postcss-modules-values@^1.3.0:
     postcss "^6.0.1"
 
 postcss-nested@^4.1.1, postcss-nested@^4.1.2:
-  version "4.1.2"
-  resolved "https://registry.yarnpkg.com/postcss-nested/-/postcss-nested-4.1.2.tgz#8e0570f736bfb4be5136e31901bf2380b819a561"
-  integrity sha512-9bQFr2TezohU3KRSu9f6sfecXmf/x6RXDedl8CHF6fyuyVW7UqgNMRdWMHZQWuFY6Xqs2NYk+Fj4Z4vSOf7PQg==
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/postcss-nested/-/postcss-nested-4.2.1.tgz#4bc2e5b35e3b1e481ff81e23b700da7f82a8b248"
+  integrity sha512-AMayXX8tS0HCp4O4lolp4ygj9wBn32DJWXvG6gCv+ZvJrEa00GUxJcJEEzMh87BIe6FrWdYkpR2cuyqHKrxmXw==
   dependencies:
-    postcss "^7.0.14"
-    postcss-selector-parser "^5.0.0"
+    postcss "^7.0.21"
+    postcss-selector-parser "^6.0.2"
 
 postcss-normalize-charset@^4.0.1:
   version "4.0.1"
@@ -8537,7 +8537,7 @@ postcss-selector-parser@^5.0.0, postcss-selector-parser@^5.0.0-rc.4:
     indexes-of "^1.0.1"
     uniq "^1.0.1"
 
-postcss-selector-parser@^6.0.0:
+postcss-selector-parser@^6.0.0, postcss-selector-parser@^6.0.2:
   version "6.0.2"
   resolved "https://registry.yarnpkg.com/postcss-selector-parser/-/postcss-selector-parser-6.0.2.tgz#934cf799d016c83411859e09dcecade01286ec5c"
   integrity sha512-36P2QR59jDTOAiIkqEprfJDsoNrvwFei3eCqKd1Y0tUsBimsq39BLp7RD+JWny3WgB1zGhJX8XVePwm9k4wdBg==
@@ -8584,10 +8584,10 @@ postcss@^6.0.1, postcss@^6.0.23, postcss@^6.0.9:
     source-map "^0.6.1"
     supports-color "^5.4.0"
 
-postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.11, postcss@^7.0.14, postcss@^7.0.18, postcss@^7.0.2, postcss@^7.0.5:
-  version "7.0.18"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.18.tgz#4b9cda95ae6c069c67a4d933029eddd4838ac233"
-  integrity sha512-/7g1QXXgegpF+9GJj4iN7ChGF40sYuGYJ8WZu8DZWnmhQ/G36hfdk3q9LBJmoK+lZ+yzZ5KYpOoxq7LF1BxE8g==
+postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.11, postcss@^7.0.14, postcss@^7.0.18, postcss@^7.0.2, postcss@^7.0.21, postcss@^7.0.5:
+  version "7.0.23"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.23.tgz#9f9759fad661b15964f3cfc3140f66f1e05eadc1"
+  integrity sha512-hOlMf3ouRIFXD+j2VJecwssTwbvsPGJVMzupptg+85WA+i7MwyrydmQAgY3R+m0Bc0exunhbJmijy8u8+vufuQ==
   dependencies:
     chalk "^2.4.2"
     source-map "^0.6.1"