perf: ⚡️ remove support for deprecated node-sass

node-sass was deprecated a while ago:
https://sass-lang.com/blog/libsass-is-deprecated

BREAKING CHANGE: 🧨 node-sass is not supported anymore. Use `sass` instead

docs/getting-started.md

@@ -31,7 +31,7 @@ $ npm install -D svelte-preprocess
 - PostCSS: `npm install -D postcss postcss-load-config`
 - SugarSS: `npm install -D postcss sugarss`
 - Less: `npm install -D less`
-- Sass: `npm install -D node-sass` or `npm install -D sass`
+- Sass: `npm install -D sass`
 - Pug: `npm install -D pug`
 - Stylus: `npm install -D stylus`
 

docs/preprocessing.md

@@ -354,7 +354,6 @@ The `scss/sass` preprocessor accepts the default sass options alongside two othe
 | Option           | Default     | Description                                                                                                                    |
 | ---------------- | ----------- | ------------------------------------------------------------------------------------------------------------------------------ |
 | `renderSync`     | `false`     | if `true`, use the sync render method which is faster for dart sass.                                                           |
-| `implementation` | `undefined` | pass the module to use to compile sass, if unspecified, `svelte-preprocess` will first look for `node-sass` and then for Sass. |
 
 You can check the [Sass API reference](https://sass-lang.com/documentation/js-api/modules#LegacyOptions) for specific Sass options. The `file` and `data` properties are not supported. Instead, use the `prependData` property if you want to prepend some content to your `scss` content.
 

package.json

@@ -33,7 +33,7 @@
     "test": "jest",
     "lint": "eslint --ext js,ts .",
     "format": "prettier --write \"**/*.{ts,js,json}\"",
-    "postinstall": "echo \"[svelte-preprocess] Don't forget to install the preprocessors packages that will be used: node-sass/sass, stylus, less, postcss & postcss-load-config, coffeescript, pug, etc...\"",
+    "postinstall": "echo \"[svelte-preprocess] Don't forget to install the preprocessors packages that will be used: sass, stylus, less, postcss & postcss-load-config, coffeescript, pug, etc...\"",
     "version": "conventional-changelog -p angular -i CHANGELOG.md -s -r 1 && git add CHANGELOG.md",
     "patch": "npm version patch -m 'chore(release): %s'",
     "minor": "npm version minor -m 'chore(release): %s'",
@@ -60,7 +60,7 @@
       "pre-commit": "lint-staged",
       "pre-push": "tsc --noEmit",
       "commit-msg": "commitlint -E HUSKY_GIT_PARAMS",
-      "post-merge": "yarn"
+      "post-merge": "pnpm install"
     }
   },
   "lint-staged": {
@@ -82,7 +82,6 @@
     "@types/babel__core": "^7.1.19",
     "@types/jest": "^27.0.2",
     "@types/node": "^14.0.11",
-    "@types/node-sass": "^4.11.3",
     "@types/stylus": "^0.48.32",
     "autoprefixer": "^9.8.0",
     "babel-minify": "^0.5.1",
@@ -93,7 +92,6 @@
     "jest": "^27.2.4",
     "less": "^3.11.3",
     "lint-staged": "^10.5.3",
-    "node-sass": "^8.0.0",
     "postcss": "^8",
     "postcss-easy-import": "^3.0.0",
     "postcss-load-config": "^3.0.0",
@@ -137,9 +135,6 @@
     "less": {
       "optional": true
     },
-    "node-sass": {
-      "optional": true
-    },
     "postcss": {
       "optional": true
     },