Update dependency postcss-loader to v4

package.json

@@ -46,7 +46,7 @@
     "node-sass": "^5.0.0",
     "path-complete-extname": "^1.0.0",
     "postcss-cssnext": "^3.0.2",
-    "postcss-loader": "3.0.0",
+    "postcss-loader": "4.0.0",
     "postcss-smart-import": "^0.7.5",
     "precss": "^4.0.0",
     "prop-types": "^15.7.2",

yarn.lock

@@ -3855,6 +3855,17 @@ cosmiconfig@^6.0.0:
     path-type "^4.0.0"
     yaml "^1.7.2"
 
+cosmiconfig@^7.0.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/cosmiconfig/-/cosmiconfig-7.1.0.tgz#1443b9afa596b670082ea46cbd8f6a62b84635f6"
+  integrity sha512-AdmX6xUzdNASswsFtmwSt7Vj8po9IuqXm0UXz7QKPuEUmPB4XyjGfaAr2PSuELMwkRMVH1EpIkX5bTZGRB3eCA==
+  dependencies:
+    "@types/parse-json" "^4.0.0"
+    import-fresh "^3.2.1"
+    parse-json "^5.0.0"
+    path-type "^4.0.0"
+    yaml "^1.10.0"
+
 create-ecdh@^4.0.0:
   version "4.0.4"
   resolved "https://registry.yarnpkg.com/create-ecdh/-/create-ecdh-4.0.4.tgz#d6e7f4bffa66736085a0762fd3a632684dabcc4e"
@@ -7914,6 +7925,11 @@ kleur@^3.0.3:
   resolved "https://registry.yarnpkg.com/kleur/-/kleur-3.0.3.tgz#a79c9ecc86ee1ce3fa6206d1216c501f147fc07e"
   integrity sha512-eTIzlVOSUR+JxdDFepEYcBMtZ9Qqdef+rnzWdRZuMbOywu5tO2w2N7rqjoANZ5k9vywhL6Br1VRjUIgTQx4E8w==
 
+klona@^2.0.3:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/klona/-/klona-2.0.6.tgz#85bffbf819c03b2f53270412420a4555ef882e22"
+  integrity sha512-dhG34DXATL5hSxJbIexCft8FChFXtmskoZYnoPWjXQuebWYCNkVeV3KkGegCK9CP1oswI/vQibS2GY7Em/sJJA==
+
 klona@^2.0.4:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/klona/-/klona-2.0.4.tgz#7bb1e3affb0cb8624547ef7e8f6708ea2e39dfc0"
@@ -10133,7 +10149,18 @@ postcss-load-config@^2.0.0:
     cosmiconfig "^5.0.0"
     import-cwd "^2.0.0"
 
-[email protected], postcss-loader@^3.0.0:
+[email protected]:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-4.0.0.tgz#bfd04521d2a2db69cb9e8a7cee0a5ae704e751dc"
+  integrity sha512-LdpfM9yCVFeJzofnaFvLf3g9oMuH2mIIqOcu81n6JHxzRNBl78GHiYWUJ5gf4c7A7VZiBCeWwfVAMw/mQCAM3Q==
+  dependencies:
+    cosmiconfig "^7.0.0"
+    klona "^2.0.3"
+    loader-utils "^2.0.0"
+    schema-utils "^2.7.1"
+    semver "^7.3.2"
+
+postcss-loader@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-3.0.0.tgz#6b97943e47c72d845fa9e03f273773d4e8dd6c2d"
   integrity sha512-cLWoDEY5OwHcAjDnkyRQzAXfs2jrKjXpO/HQFcc5b5u/r7aa471wdmChmwfnv7x2u840iat/wi0lQ5nbRgSkUA==
@@ -11794,7 +11821,7 @@ schema-utils@^1.0.0:
     ajv-errors "^1.0.0"
     ajv-keywords "^3.1.0"
 
-schema-utils@^2.6.1, schema-utils@^2.6.5, schema-utils@^2.7.0:
+schema-utils@^2.6.1, schema-utils@^2.6.5, schema-utils@^2.7.0, schema-utils@^2.7.1:
   version "2.7.1"
   resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-2.7.1.tgz#1ca4f32d1b24c590c203b8e7a50bf0ea4cd394d7"
   integrity sha512-SHiNtMOUGWBQJwzISiVYKu82GiV4QYGePp3odlY1tuKO7gPtphAT5R/py0fA6xtbgLL/RvtJZnU9b8s0F1q0Xg==
@@ -14069,6 +14096,11 @@ yallist@^4.0.0:
   resolved "https://registry.yarnpkg.com/yallist/-/yallist-4.0.0.tgz#9bb92790d9c0effec63be73519e11a35019a3a72"
   integrity sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==
 
+yaml@^1.10.0:
+  version "1.10.2"
+  resolved "https://registry.yarnpkg.com/yaml/-/yaml-1.10.2.tgz#2301c5ffbf12b467de8da2333a459e29e7920e4b"
+  integrity sha512-r3vXyErRCYJ7wg28yvBY5VSoAF8ZvlcW9/BwUzEtUsjvX/DKs24dIkuwjtuprwJJHsbyUbLApepYTR1BN4uHrg==
+
 yaml@^1.7.2:
   version "1.10.0"
   resolved "https://registry.yarnpkg.com/yaml/-/yaml-1.10.0.tgz#3b593add944876077d4d683fee01081bd9fff31e"