Bump gatsby-plugin-postcss from 2.3.2 to 2.3.6

Bumps [gatsby-plugin-postcss](https://github.com/gatsbyjs/gatsby/tree/HEAD/packages/gatsby-plugin-postcss) from 2.3.2 to 2.3.6.
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-plugin-postcss/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/commits/gatsby-plugin-postcss@2.3.6/packages/gatsby-plugin-postcss)

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

Author: dependabot-preview[bot]

yarn.lock

@@ -850,10 +850,10 @@
     "@babel/plugin-transform-react-jsx-source" "^7.10.4"
     "@babel/plugin-transform-react-pure-annotations" "^7.10.4"
 
-"@babel/runtime@^7.6.3", "@babel/runtime@^7.8.4", "@babel/runtime@^7.9.6":
-  version "7.10.2"
-  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.10.2.tgz#d103f21f2602497d38348a32e008637d506db839"
-  integrity sha512-6sF3uQw2ivImfVIl62RZ7MXhO2tap69WeWK57vAaimT6AZbE4FbqjdEJIN1UqoD6wI6B+1n9UiagafH1sxjOtg==
+"@babel/runtime@^7.10.3", "@babel/runtime@^7.6.3", "@babel/runtime@^7.8.4":
+  version "7.10.4"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.10.4.tgz#a6724f1a6b8d2f6ea5236dbfe58c7d7ea9c5eb99"
+  integrity sha512-UpTN5yUJr9b4EX2CnGNWIvER7Ab83ibv0pcvvHc4UOdrBI5jb8bj+32cCwPX6xu0mt2daFNjYhoi+X7beH0RSw==
   dependencies:
     regenerator-runtime "^0.13.4"
 
@@ -5253,11 +5253,11 @@ gatsby-plugin-css-modules-flow-types@^0.1.1:
     css-modules-flow-types-loader "^1.1.1"
 
 gatsby-plugin-postcss@^2.0.2:
-  version "2.3.2"
-  resolved "https://registry.yarnpkg.com/gatsby-plugin-postcss/-/gatsby-plugin-postcss-2.3.2.tgz#41e8a0f8e73d9a437d8a5e22be0d3b8afa897830"
-  integrity sha512-+2Ya8L+mnXp2jFVNXy/0xRwjF5HE++JtDS1d4IOO5NvlW+2Ofi5bVpO/p4TMllaVPsXBakHAT+GbDQvHVYsYDg==
+  version "2.3.6"
+  resolved "https://registry.yarnpkg.com/gatsby-plugin-postcss/-/gatsby-plugin-postcss-2.3.6.tgz#d0d8b19f9edf845b54ea49a2cdd9ceb2a52f10f5"
+  integrity sha512-rJ7GihxGc6pA3KapR2kFPYkDyVc/18Yt2nROxL893epv2nYn99H2XaeLOFvglr6FrpFkJP0TvUvwDOfQOuTz8A==
   dependencies:
-    "@babel/runtime" "^7.9.6"
+    "@babel/runtime" "^7.10.3"
     postcss-loader "^3.0.0"
 
 gauge@~2.7.3: