Allow sass-loader ^12.0.0, close #996

The only breaking change is that the minimum supported Node.js is 12.13.0,
see https://github.com/webpack-contrib/sass-loader/blob/master/CHANGELOG.md#1200-2021-06-01.

Author: Kocal

package.json

@@ -87,7 +87,7 @@
     "preact": "^8.2.1 || ^10.0.0",
     "preact-compat": "^3.17.0",
     "sass": "^1.17.0",
-    "sass-loader": "^9.0.1 || ^10.0.0 || ^11.0.0",
+    "sass-loader": "^9.0.1 || ^10.0.0 || ^11.0.0 || ^12.0.0",
     "sinon": "^9.0.2",
     "stimulus": "^2.0.0",
     "strip-ansi": "^6.0.0",

yarn.lock

@@ -6219,10 +6219,10 @@ safe-buffer@>=5.1.0, safe-buffer@^5.0.1, safe-buffer@^5.1.0, safe-buffer@^5.1.2,
   resolved "https://registry.yarnpkg.com/safer-buffer/-/safer-buffer-2.1.2.tgz#44fa161b0187b9549dd84bb91802f9bd8385cd6a"
   integrity sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==
 
-"sass-loader@^9.0.1 || ^10.0.0 || ^11.0.0":
-  version "11.1.1"
-  resolved "https://registry.yarnpkg.com/sass-loader/-/sass-loader-11.1.1.tgz#0db441bbbe197b2af96125bebb7f4be6476b13a7"
-  integrity sha512-fOCp/zLmj1V1WHDZbUbPgrZhA7HKXHEqkslzB+05U5K9SbSbcmH91C7QLW31AsXikxUMaxXRhhcqWZAxUMLDyA==
+"sass-loader@^9.0.1 || ^10.0.0 || ^11.0.0 || ^12.0.0":
+  version "12.0.0"
+  resolved "https://registry.yarnpkg.com/sass-loader/-/sass-loader-12.0.0.tgz#ba91df5725cb9676c8e0937002a647ab011eb94a"
+  integrity sha512-LJQMyDdNdhcvoO2gJFw7KpTaioVFDeRJOuatRDUNgCIqyu4s4kgDsNofdGzAZB1zFOgo/p3fy+aR/uGXamcJBg==
   dependencies:
     klona "^2.0.4"
     neo-async "^2.6.2"