Fix postcss vulnerability in cssnano (opensearch-project#584)

Signed-off-by: Andrey Myssak <[email protected]>
Co-authored-by: Sergey Myssak <[email protected]>

package.json

@@ -65,6 +65,7 @@
     "**/scss-tokenizer": "^0.4.3",
     "**/node-notifier": "^10.0.1",
     "**/got": "^11.8.5",
+    "cssnano/**/postcss": "^7.0.39",
     "**/eslint": "^7.10.0",
     "**/har-validator": "^5.1.5",
     "**/d3-color": "^3.1.0",

yarn.lock

@@ -12988,16 +12988,7 @@ [email protected]:
     indexes-of "^1.0.1"
     uniq "^1.0.1"
 
-postcss@^6.0.0:
-  version "6.0.23"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.23.tgz#61c82cc328ac60e677645f979054eb98bc0e3324"
-  integrity sha512-soOk1h6J3VMTZtVeVpv15/Hpdl2cBLX3CAw4TAbkpTJiNPk9YP/zWcD1ND+xEtvyuuvKzbxliTOIyvkSeSJ6ag==
-  dependencies:
-    chalk "^2.4.1"
-    source-map "^0.6.1"
-    supports-color "^5.4.0"
-
-postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.27, postcss@^7.0.32, postcss@^7.0.5, postcss@^7.0.6:
+postcss@^6.0.0, postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.27, postcss@^7.0.32, postcss@^7.0.39, postcss@^7.0.5, postcss@^7.0.6:
   version "7.0.39"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.39.tgz#9624375d965630e2e1f2c02a935c82a59cb48309"
   integrity sha512-yioayjNbHn6z1/Bywyb2Y4s3yvDAeXGOyxqD+LnVOinq6Mdmd++SW2wUNVzavyyHxd6+DxzWGIuosg6P1Rj8uA==
@@ -15556,7 +15547,7 @@ supports-color@^4.0.0:
   dependencies:
     has-flag "^2.0.0"
 
-supports-color@^5.3.0, supports-color@^5.4.0:
+supports-color@^5.3.0:
   version "5.5.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-5.5.0.tgz#e2e69a44ac8772f78a1ec0b35b689df6530efc8f"
   integrity sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==