removed slimselect node_module patche as not necessary anymore

package.json

@@ -9,8 +9,7 @@
     "lint": "eslint --ext .js,.vue src",
     "lint:fix": "eslint --ext .js,.vue src --fix",
     "test": "jest --config test/jest.config.js",
-    "test:debug": "node --inspect node_modules/.bin/jest --runInBand --config test/jest.config.js",
-    "postinstall": "patch --forward node_modules/slim-select/package.json < patches/slimselect-export-css.patch"
+    "test:debug": "node --inspect node_modules/.bin/jest --runInBand --config test/jest.config.js"
   },
   "keywords": [
     "Vue",