Remove tailwindcss dependency

Fixes facebook#12044

Installing tailwindcss comes with a bunch of junk most people don't need, and at least prettier-plugin-tailwindcss but possibly more subdependecies are unlicensed which makes usage troublesome.

Author: MartijnHols

packages/react-scripts/config/webpack.config.js

@@ -68,10 +68,18 @@ const imageInlineSizeLimit = parseInt(
 // Check if TypeScript is setup
 const useTypeScript = fs.existsSync(paths.appTsConfig);
 
+const hasTailwindcss = (() => {
+  try {
+    require.resolve('tailwindcss');
+    return true;
+  } catch (e) {
+    return false;
+  }
+})();
 // Check if Tailwind config exists
-const useTailwind = fs.existsSync(
-  path.join(paths.appPath, 'tailwind.config.js')
-);
+const useTailwind =
+  hasTailwindcss &&
+  fs.existsSync(path.join(paths.appPath, 'tailwind.config.js'));
 
 // Get the path to the uncompiled service worker (if it exists).
 const swSrc = paths.swSrc;

packages/react-scripts/package.json

@@ -69,7 +69,6 @@
     "semver": "^7.3.5",
     "source-map-loader": "^3.0.0",
     "style-loader": "^3.3.1",
-    "tailwindcss": "^3.0.2",
     "terser-webpack-plugin": "^5.2.5",
     "webpack": "^5.64.4",
     "webpack-dev-server": "^4.6.0",