Update dependency sass-loader to v8 (https://github.com/woocommerce/woocommerce-admin/pull/3925)

* Update dependency sass-loader to v8

* Address node-sass webpack breaking changes

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Paul Sealock <psealock@gmail.com>

plugins/woocommerce-admin/package-lock.json

@@ -23623,18 +23623,30 @@
       }
     },
     "sass-loader": {
-      "version": "7.3.1",
-      "resolved": "https://registry.npmjs.org/sass-loader/-/sass-loader-7.3.1.tgz",
-      "integrity": "sha512-tuU7+zm0pTCynKYHpdqaPpe+MMTQ76I9TPZ7i4/5dZsigE350shQWe5EZNl5dBidM49TPET75tNqRbcsUZWeNA==",
+      "version": "8.0.2",
+      "resolved": "https://registry.npmjs.org/sass-loader/-/sass-loader-8.0.2.tgz",
+      "integrity": "sha512-7o4dbSK8/Ol2KflEmSco4jTjQoV988bM82P9CZdmo9hR3RLnvNc0ufMNdMrB0caq38JQ/FgF4/7RcbcfKzxoFQ==",
       "dev": true,
       "requires": {
         "clone-deep": "^4.0.1",
-        "loader-utils": "^1.0.1",
-        "neo-async": "^2.5.0",
-        "pify": "^4.0.1",
+        "loader-utils": "^1.2.3",
+        "neo-async": "^2.6.1",
+        "schema-utils": "^2.6.1",
         "semver": "^6.3.0"
       },
       "dependencies": {
+        "ajv": {
+          "version": "6.12.0",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.0.tgz",
+          "integrity": "sha512-D6gFiFA0RRLyUbvijN74DWAjXSFxWKaWP7mldxkVhyhAV3+SWA9HEJPHQ2c9soIeTFJqcSdFDGFgdqs1iUU2Hw==",
+          "dev": true,
+          "requires": {
+            "fast-deep-equal": "^3.1.1",
+            "fast-json-stable-stringify": "^2.0.0",
+            "json-schema-traverse": "^0.4.1",
+            "uri-js": "^4.2.2"
+          }
+        },
         "clone-deep": {
           "version": "4.0.1",
           "resolved": "https://registry.npmjs.org/clone-deep/-/clone-deep-4.0.1.tgz",
@@ -23646,6 +23658,16 @@
             "shallow-clone": "^3.0.0"
           }
         },
+        "schema-utils": {
+          "version": "2.6.5",
+          "resolved": "https://registry.npmjs.org/schema-utils/-/schema-utils-2.6.5.tgz",
+          "integrity": "sha512-5KXuwKziQrTVHh8j/Uxz+QUbxkaLW9X/86NBlx/gnKgtsZA2GIVMUn17qWhRFwF8jdYb3Dig5hRO/W5mZqy6SQ==",
+          "dev": true,
+          "requires": {
+            "ajv": "^6.12.0",
+            "ajv-keywords": "^3.4.1"
+          }
+        },
         "semver": {
           "version": "6.3.0",
           "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",

plugins/woocommerce-admin/package.json

@@ -207,7 +207,7 @@
 		"request-promise": "4.2.5",
 		"rimraf": "3.0.2",
 		"rtlcss": "2.5.0",
-		"sass-loader": "7.3.1",
+		"sass-loader": "8.0.2",
 		"style-loader": "0.23.1",
 		"stylelint": "9.10.1",
 		"stylelint-config-wordpress": "13.1.0",

plugins/woocommerce-admin/webpack.config.js

@@ -158,9 +158,13 @@ const webpackConfig = {
 					},
 					{
 						loader: 'sass-loader',
-						query: {
-							includePaths: [ 'client/stylesheets/abstracts' ],
-							data:
+						options: {
+							sassOptions: {
+								includePaths: [
+									'client/stylesheets/abstracts',
+								],
+							},
+							prependData:
 								'@import "node_modules/@wordpress/base-styles/_colors.scss"; ' +
 								'@import "node_modules/@wordpress/base-styles/_variables.scss"; ' +
 								'@import "node_modules/@wordpress/base-styles/_mixins.scss"; ' +